430 results on '"fatigue damage"'
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2. Temperature effects on fatigue properties of plain-woven composites by an acoustic-optical-thermal multi-information fusion method
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Liu, Xiaodong, Huang, Kai, Zhou, Jindi, Han, Xiaojian, Dong, Erqin, Zhang, Li, and Guo, Licheng
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- 2025
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3. Fatigue damage and life prediction for AISI H13 steel under cyclic thermomechanical loading
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Wu, Boya, Liu, Meichen, Xu, Guocai, Zhu, Yan, Li, Junwan, and Wu, Xiaochun
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- 2025
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4. Creep-thermal fatigue behavior of thin-walled structures with holes and a creep-thermal fatigue-oxidation phase field model.
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Du, Chenyu, Cui, Haitao, and Zhang, Hongjian
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THIN-walled structures , *DAMAGE models , *FATIGUE cracks , *THERMAL fatigue , *CRACK propagation (Fracture mechanics) - Abstract
[Display omitted] • Evaluated creep-thermal fatigue (CTF) behavior of thin-walled structures with holes. • Developed a creep-thermal fatigue-oxidation phase field model. • Constructed a creep degradation function based on classical damage theory. • Introduced strategies to describe oxidation-induced fatigue damage. • Validated the effectiveness of the model in predicting CTF and creep-fatigue life. An experiment was conducted to evaluate the creep-thermal fatigue (CTF) behavior of thin-walled structures with holes. To achieve this, a high-temperature hold phase was added in the testing. The crack propagation of CTF is driven by the combined effects of creep, thermal fatigue, and oxidation. Therefore, a creep-thermal fatigue-oxidation phase field model was developed to simulate CTF behavior. The model accounts for the interaction between creep damage and fatigue damage, as well as the oxidation effect. A creep degradation function was formulated based on classical damage theory, and two creep damage models were compared. Two physically meaningful strategies were proposed to describe oxidation-induced fatigue damage. Finally, the applicability of model to creep-fatigue was validated. [ABSTRACT FROM AUTHOR] more...
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- 2025
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5. Heterogeneity induced fracture characterization of concrete under fatigue loading using digital image correlation and acoustic emission techniques.
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Dubey, Sandeep, Kumar, Bineet, and Ray, Sonalisa
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FATIGUE crack growth , *FRACTURE mechanics , *DIGITAL image correlation , *FATIGUE life , *FATIGUE cracks , *CONCRETE fatigue , *ACOUSTIC emission - Abstract
Understanding the fatigue failure mechanisms in concrete is complex and remains an area of ongoing investigation. Material heterogeneity, along with the size effect, plays a significant role in specifying the crack propagation behaviour and fatigue life in case of repetitive loading conditions. In this study, the influence of material heterogeneity on the fatigue behaviour of concrete has been examined. Three different-size beam specimens with varying heterogeneity (aggregate sizes) have been considered to investigate various fracture characteristics under repetitive load conditions. Acoustic emission and digital image correlation techniques have been employed to analyse crack growth behaviour. The results revealed that stiffness degradation and crack propagation rates are faster for the specimens with smaller aggregate sizes compared to the larger aggregate size specimens of the same depth. Moreover, the fatigue life and effective crack length at failure are also higher in the case of larger aggregate sizes compared to smaller ones. Therefore, a heterogeneity-adjusted, analytical model of fatigue crack growth has been proposed. Further, the AE parameters have been utilized to characterize the tensile and shear crack dominance in different stages of fatigue crack propagation. The outcome of this study can be utilized to anticipate the crack propagation behaviour and residual fatigue life for any combination of specimen size and aggregate size. • The present study focuses on fatigue analysis in concrete considering material heterogeneity. • The work considers three different specimen sizes and aggregate sizes to demonstrate its influence. • The research proposes a heterogeneity adjusted fatigue crack growth model for concrete. • AE parameters have been utilized to characterize the tensile and shear crack dominancy. [ABSTRACT FROM AUTHOR] more...
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- 2024
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6. Study on low fatigue damage behavior of TC17 titanium alloy with basket-weave microstructure.
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Lu, Yanli, Jiang, Jialiang, Wang, Hong, Dang, Hanrui, and He, Menghan
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FATIGUE cracks , *STRAINS & stresses (Mechanics) , *MICROSTRUCTURE , *SOLUTION strengthening , *TITANIUM alloys , *CRACK propagation (Fracture mechanics) - Abstract
• The cyclic deformation behavior and fatigue fracture mechanism of TC17 alloy under different strain amplitudes were investigated. • The microscopic causes of the cyclic softening/hardening phenomenon were analyzed. • The relationship between defects (secondary cracks, holes) and the basket-weave microstructure was explored. • The variations in microstructure surrounding the crack propagation path were elucidated. Room-temperature low-fatigue tests were conducted on TC17 titanium alloy, and the low-fatigue damage behavior of TC17 titanium alloy with a basket-weave microstructure at room temperature was investigated. The results show that TC17 titanium alloy exhibits different cyclic hardening/softening phenomena at different strain amplitude (ε ta ) levels, which was closely related to the magnitude of strain amplitude, the crack sources of all specimens generated on the surface, and the number of crack sources increases with the increase of strain amplitude level. The competitive relationship between back stress hardening and frictional stress softening caused by changes in different microstructures is the reason for the occurrence of different cyclic hardening/softening phenomena. The relationship between the holes and secondary cracks near the fracture surface and the basket-weave microstructure was further discussed. The secondary cracks/holes were more likely to initiate in the primary α phase where the solid solution strengthening effect was weak. In addition, the interaction between the secondary crack propagation path and the nearby α lamellae was studied by the Electron Backscatter Diffraction (EBSD) method. [ABSTRACT FROM AUTHOR] more...
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- 2024
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7. A damage constitutive model for consistent description of static and fatigue behaviors of ultra-high performance concrete containing coarse aggregate.
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Li, Lijian, Huang, Le, Chi, Yin, and Xu, Lihua
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DAMAGE models , *STRESS waves , *THEORY of wave motion , *CONCRETE fatigue , *DEAD loads (Mechanics) , *MATERIAL plasticity , *MECHANICAL loads , *VISCOPLASTICITY - Abstract
[Display omitted] • A consistent damage evolution rule is developed for the uniform expression of damage evolution of UHPC-CA at varying loading conditions. • A damage constitutive model is established for UHPC-CA with the driving and alleviating effects induced by the inclusions of coarse aggregate and steel fiber taken into consideration. • A user-defined UMAT subroutine is compiled for the numerical implementation of the proposed model. A suitable constitutive model for describing the mechanical behaviors of ultra-high performance concrete (UHPC) under various loading histories plays a vital role in analyzing its structural performance. In this work, a consistent elastoplastic damage model is developed for UHPC containing coarse aggregate (UHPC-CA) subjected to static and fatigue loads, in which the driving and alleviating effects induced by the inclusions of coarse aggregate and steel fiber are considered. For damage evolution, based on the acting mechanism of the non-uniformity of stress wave propagation determined by the loading rate on the mechanical responses of UHPC-CA, the loading rate is skillfully integrated into the damage evolution rule to achieve the consistent description of mechanical behaviors of UHPC-CA under static and fatigue loading conditions. Regarding plasticity growth, an empirical plastic deformation model is adopted to improve the computational efficiency of structural nonlinear analysis. To verify the applicability of the proposed model, a user-defined UMAT subroutine is further developed for the subsequent numerical implementation. The comprehensive comparisons between the numerical predictions and independent experimental results at both the material level and structural level solidly demonstrate the capacity of the consistent model to capture the main features concerning the mechanical performance of UHPC-CA subjected to different loading paths. [ABSTRACT FROM AUTHOR] more...
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- 2024
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8. Characterization and application of maximum entropy fatigue damage model based on digital image correlation and inverse analysis.
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Chen, Xing, Ju, Xiaozhe, Ruan, Hongshi, Shan, Qingpeng, Wang, Yijian, Xu, Yangjian, Chen, Junjun, Liang, Lihua, and Xie, Shaojun
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DAMAGE models , *FATIGUE cracks , *DIGITAL image correlation , *STATISTICAL correlation , *ENTROPY - Abstract
In this study, a progress damage model that integrates the Maximum Entropy Fracture Model (MEFM) with the A-F kinematic hardening model is proposed to characterize the low-cycle fatigue damage behavior of metals. The MEFM establishes a correlation between the damage value and cumulative dissipation at the integration point through a damage accumulation parameter. Concurrently, the constitutive relationship of the material is delineated by the A-F kinematic hardening model. To shift enhance both efficiency and accuracy of obtaining model parameters, this study employs the inverse analysis techniques to derive damage accumulation parameter and material properties, departing from the conventional approach of experimental data fitting. Uniaxial tensile fatigue experiments were conducted on copper to validate the efficacy of the progressive damage model, which is also a key step in the process of inverse analysis. Digital Image Correlation (DIC) was employed to rectify the post-test displacement field, with the corrected displacement serving as a boundary condition in simulations. Comparisons between simulation results and experimental data highlight the capability of the developed progressive damage model. This model demonstrates effectiveness in predicting the formation and propagation of low-cycle fatigue damage in ductile metal materials, leading to ultimate failure. • A damage model used for predicting low-cycle fatigue failure was developed. • The Kalman filtering algorithm was used to inversely identify damage parameters. • The Nelder–Mead algorithm was used to inversely identify material parameters. • The DIC technique was used to correct boundary conditions in fatigue simulation. [ABSTRACT FROM AUTHOR] more...
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- 2024
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9. Monitoring and quantification of ultrasonic fatigue damage in copper based on internal friction measurement.
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Liu, Bofeng and Li, Faxin
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FATIGUE cracks , *COPPER , *INTERNAL friction , *METAL fatigue , *FRICTION measurements , *ULTRASONIC testing - Abstract
• An automated system is developed for ultrasonic fatigue and internal friction testing. • Fatigue damage can be effective monitored using system damping. • Internal frictions of damaged copper specimens are over 3 times of fresh specimens. • Yield stresses of damaged specimens are obviously lower than the fresh specimens. • A practical damage variable based on internal friction is proposed. Fatigue damage in metals and alloys would reduce their strength and should be identified as early as possible. However, fatigue damage is usually difficult to detect even using advanced nondestructive testing method. Here we developed an automated damping monitoring system for ultrasonic fatigue testing based on a quantitative electromechanical impedance method. During fatigue testing, the damping and resonance frequency of the Piezo actuator/horn/specimen system is measured regularly using an impedance analyzer. When the system damping suddenly increases, it implies that fatigue damage may be generated in the specimen. Separate impedance measurements on the copper specimen in a vacuum chamber show that the internal frictions of damaged specimens are much larger than the fresh specimens. Subsequent X-Ray micro-CT scanning shows that microcracks up to 0.8 mm in length were generated in those fatigued specimens with increased internal frictions. Further tensile testing shows that compared to the fresh specimen, specimens with fatigue damage exhibits reduced tensile strength and elongation at break. Furthermore, the larger the internal friction, the smaller the remaining yield strength and a nearly linear relationship between them holds. Finally, a damage variable D Q is defined based on internal friction which can act as a measure of fatigue damage in metals. [ABSTRACT FROM AUTHOR] more...
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- 2024
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10. Damage assessment during ultrasonic fatigue testing of a CF-PEKK composite using self-heating phenomenon.
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Premanand, Aravind, Rienks, Michael, and Balle, Frank
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ULTRASONIC testing , *FATIGUE testing machines , *FATIGUE cracks , *MATERIAL fatigue , *CYCLIC loads , *HIGH cycle fatigue , *CYCLIC fatigue - Abstract
The knowledge and experience with the very high cycle fatigue (VHCF) behavior are limited compared to the low cycle and high cycle fatigue behavior of fiber-reinforced composite materials. Accelerated cyclic loading using an ultrasonic fatigue testing system is one potential solution to evaluate the longevity of composite materials within a reasonable time. Insufficient sampling rates and the inherent inaccuracies of non-contact measurement devices pose critical challenges in the adaptation of accelerated fatigue experiments. This study aims to overcome these challenges by combining the temperature response of the composite specimen and the input parameters for the dynamic response of the in-house developed ultrasonic fatigue testing system to detect damage before failure. Increasing- and constant-amplitude fatigue experiments were conducted on a carbon fiber satin fabric-reinforced poly-ether-ketone-ketone (CF-PEKK) composite material. These experiments were carried out under three-point bending loading conditions at a cyclic frequency of about 20 kHz. Various parameters, such as the surface temperature, the cyclic displacement, and the input resonance parameters of the ultrasonic generator, were recorded during these experiments. The VHCF behavior of the CF-PEKK material system was characterized based on these results and through digital light optical microscopy. • Self-heating phenomenon can be used to characterize fatigue damage during UFT. • The thermal and dynamic responses due to damage accumulation show good agreement. • Fatigue damage can be captured with in-situ techniques at sampling rates much less than 20 kHz. [ABSTRACT FROM AUTHOR] more...
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- 2024
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11. On the role of the spherulitic microstructure in fatigue damage of pure polymer and glass-fiber reinforced semi-crystalline polyamide 6.6.
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Raphael, I., Saintier, N., Robert, G., Béga, J., and Laiarinandrasana, L.
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• Fatigue damage progresses in the polymer by opening each spherulite in its equatorial plane. • Half of the spherulite can be observed on each fracture surface, with the nuclei being perfectly visible. • Injection-molding induces an orientation of the spherulitic structure. • Oriented spherulites are intermediate between the usual radial spherulite and the oriented shish-kebab. Understanding fatigue damage mechanisms in short fiber reinforced thermoplastics is a key issue in order to optimize material processing and propose physically based multiscale fatigue damage models. The present work aims at further understanding observations of fatigue damage in the polyamide 6.6 matrix with respect to its semi-crystalline structure. In this paper the polymer and associated composite are tested in their ductile regime i.e. above the glass transition temperature. Tomographic and SEM observations are used in order to establish a damage scenario at the spherulitic scale. These observations prove that fatigue damage progresses by intra-spherulitic failure in their equatorial plane. Observations of the spherulite nuclei also evidence the oriented structure of the semi-crystalline polymer induced by the injection-molding manufacturing process. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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12. Fatigue property and microstructure deformation behavior of multiphase microstructure in a medium-carbon bainite steel under rolling contact condition.
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Li, Qiangguo, Huang, Xuefei, and Huang, Weigang
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ROLLED steel , *ROLLING contact , *ROLLING (Metalwork) , *ROLLING contact fatigue , *BAINITIC steel , *MICROSTRUCTURE - Abstract
• The multiphase microstructure obtained by B-QP process shows better RCF properties. • The B-QP steel with multiphase microstructure exhibits the better wear resistant. • The multiphase microstructure has higher hardness increasing ratios after RCF test. • The multiphase microstructure shows the larger strain accumulation under RCF test. • The RCF damage level of the multiphase microstructure is lower. Bainitic steel is considered to be the best potential candidate steel for rails due to its high strength and excellent toughness. The objective of this work was to investigate the fatigue property and microstructure deformation behavior of a medium-carbon bainitic steel with bainite/martensite/retained austenite multiphase microstructure obtained by a modified Q&P process (B-QP) under rolling contact condition. The analysis results of TEM indicated that the multiphase microstructure consists of lath bainitic ferrite, lath martensitic ferrite and film-like retained austenite which distributes mainly between bainite and martensite laths. The results showed that the multiphase microstructure has a better combination of toughness (103 J), hardness (47.8 HRC) and elongation (18.6%), along with better rolling contact fatigue (RCF) properties and wear resistance than that of full bainite microstructure obtained by the austempering process (BAT). After the steel subjected to 105 cycles of RCF testing, nanocrystalline grains (approximately 93 nm and 67 nm for the BAT and B-QP sample, respectively) were obtained at the deformed layer depth of 10 μm. Meanwhile, the multiphase microstructure demonstrated a higher microhardness increasing ratio (24.5%) than that of the full bainite (21.2%) and a larger plastic deformation zone (103 μm). The EBSD and XRD analysis indicated that the multiphase microstructure has a lower stress concentration possibility and higher percentage of high-angle boundaries as well as some film-like austenite retained in the plastic deformation layer. In addition, many pits on the contact surface of the BAT sample appeared, due to spalling damage caused by cyclic loading, and the crack propagation depth was larger. Conversely, the contact surface of the B-QP sample with a multiphase microstructure looked smooth, and the crack propagation depth was shallow under the contact surface. The enhanced rolling contact fatigue properties and wear resistance of multiphase microstructure can be mainly attributed to better a combination of strength and toughness, larger plastic strain accumulation and lower fatigue damage level. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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13. Reversible phenomena and fatigue damage during cyclic loading and rest periods on bitumen.
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Babadopulos, Lucas F. de A.L., Orozco, Gabriel, Sauzéat, Cédric, and Di Benedetto, Hervé
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REST periods , *MATERIAL fatigue , *MODULUS of rigidity , *CYCLIC loads , *BITUMEN - Abstract
• Nonlinearity, thixotropy and self-heating are relevant during fatigue tests. • A method for separating reversible phenomena effects from damage is proposed. • Damage induces linear modulus decrease with fixed strain amplitude load repetitions. • Damage does not produce change in bitumen phase angle. • Nonlinearity and thixotropy seem to be fundamentally related. This paper investigates the effects of reversible phenomena (nonlinearity, self-heating and thixotropy) and damage on bitumen. Four specimens were subjected to different cyclic loading tests: complex shear modulus ( G ∗ ), strain amplitude sweeps (SAS) and Loading and Rest Periods (LRP). LRP test consists of applying series of cyclic loading at high strain amplitude (γ 0), such as in classical fatigue tests, followed by rest periods (five repetitions). During rest, G* was regularly measured. Specimen temperature was carefully measured during all tests. 2S2P1D rheological model was used along with G ∗ tests to characterise linear viscoelastic behaviour, and to calculate the self-heating effect on the measured G ∗ during LRP test. SAS results were used to evaluate nonlinearity effect. LRP results showed that temperature may significantly increase during loading. About 5 °C increase was observed after 10,000 cycles with γ 0 = 2%. Such increase results in 70% to 80% modulus decrease, depending on the analysed γ 0. Damage was found to cumulate linearly with the total number of applied cycles at fixed γ 0 , with negligible phase angle variation. After correcting temperature and damage effects, thixotropy evolution could be observed on Black diagrams, where a shared direction with nonlinearity was observed. This suggests a shared intrinsic mechanism, possibly on the microstructural level. Finally, it is clear that reversible phenomena play an important role on the measured G ∗ , especially at higher γ 0. Such effects could not be neglected for the analysed LRP tests (whose loading part is similar to classical fatigue tests). Tests producing less reversible effects should be preferred. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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14. Creep effects on tension-tension fatigue behavior of angle-ply GFRP composite laminates.
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Movahedi-Rad, A. Vahid, Keller, Thomas, and Vassilopoulos, Anastasios P.
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CREEP (Materials) , *LAMINATED materials - Abstract
Highlights • Creep-fatigue interaction in (±45) 2s glass/epoxy composite laminates was studied. • Fatigue loading was interrupted by creep at the maximum stress level. • Fatigue behavior was affected by hold loads (creep). • Damage was observed at the early stages of pure creep. • Fatigue damage accelerated the creep strain development during the hold time. Abstract Angle-ply (±45) 2S glass/epoxy composite specimens have been subjected to pure creep and tension-tension constant amplitude fatigue loading interrupted at σ max by creep intervals lasting for 2 or 48 h in order to examine the effects of creep loading on the fatigue response and vice versa. The specimens' behavior and damage status were continuously monitored during the experiments; strains were measured by a video extensometer, the self-generated temperature on the specimens' surface was recorded by an infrared camera, while a digital camera with sufficient backlighting was used in order to capture the damage development in the translucent specimens throughout the experiment. Post-mortem photos were taken by a digital microscope for the analysis of the fracture surfaces. In comparison to continuous fatigue, applying the creep-fatigue loading pattern with a 2-h creep time at low stress levels had no effect on fatigue life. However, as the stress level increased, specimen stiffening occurred during creep loading because of the glass fiber realignment, which also decreased the internal friction, hysteresis loop area, and self-generated temperature, thus prolonging the fatigue life. The restoring of fatigue stiffness was greater at a creep time of 48 h due to more creep strain, which led to more fiber realignment. However, the higher creep strain at high stress levels caused more creep damage and thus resulted in a shorter fatigue life. In addition, it was observed that the fatigue damage accelerated creep deformation. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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15. Effect of a magnetic field applied during fusion welding on the fatigue damage of 2205 duplex stainless steel joints.
- Author
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Rosado-Carrasco, J., Krupp, U., López-Morelos, V.H., Giertler, A., García-Rentería, M.A., and González-Sánchez, J.
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MAGNETIC fields , *FUSION welding , *DUPLEX stainless steel , *STEEL fatigue , *HIGH cycle fatigue - Abstract
Highlights • Magnetic field applied during welding of 2205 duplex steel improved fatigue resistance. • Magnetic field induced ferrite grain refinement, high regenerated austenite in the HAZ. • Improved microstructure increased number of microstructure barriers for crack growth. • Crack initiation needed more load cycles on samples welded under 3 mT magnetic field. • More plastic deformation was induced on austenite before fatigue crack initiation. Abstract The effect of the application of a 3 mT electromagnetic field (EMF) during the welding of a 2205 duplex stainless steel on the resistance to fatigue damage was investigated on samples subjected to high cycle fatigue (HCF) and very high cycle fatigue (VHCF) conditions. Ferrite grain refinement, high volume fraction of regenerated austenite in the heat affected zone and smaller columnar grains in the weld metal were induced by (EMF) application during gas metal arc welding. The improved microstructure evolution during the thermal cycle increased the number of microstructural barriers, hindering the nucleation and growth of microstructurally short fatigue cracks. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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16. Assessing the fatigue damage of concrete structures using automatically classified crack severity level information.
- Author
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Sun, Hongshuo, Song, Li, and Yu, Zhiwu
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CONCRETE fatigue , *FATIGUE cracks , *TRANSFORMER models , *FATIGUE life , *CYCLIC loads , *MATERIAL fatigue , *PLANT shoots - Abstract
• A quantitative index of regional complex crack severity level is proposed. • The regional crack severity level classification testing set F1 score reached 0.9903. • A method for efficiently assessing fatigue damage by crack information is proposed. The aim of this paper is to assess the fatigue damage of concrete structures using automatically classified crack severity level information. To solve the problem that the label data used for the automatic classification of regional complex crack severity levels can only be labeled by intuition, this paper proposes a quantitative index of regional complex crack severity levels that can consider the regional crack width, height, and density information. The testing set F1 score of the Swin Transformer classification model trained by the label data reaches 0.9903. To investigate the feasibility of assessing the concrete structure fatigue damage based on the crack change information, the paper adopted the scanning shooting method to acquire the concrete beam panoramas at different cyclic loading times in the fatigue test, and automatically classified the crack severity levels in different regions of the panoramas using the Swin transformer. The test results show that the information on the change in the number of regions with the same crack severity level on the concrete structure surface can be used to estimate approximately the fatigue life percentage interval that the concrete structure is currently in, which provides a reference for the development of maintenance measures and safety warnings. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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17. Wheel load reconstruction using strain gauge measurements on the bogie frame for strain prediction and fatigue assessment
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Vesa Nieminen, Antero Tuohineva, and Maija Autio
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Virtual sensing ,Bogie frame ,Mechanics of Materials ,Mechanical Engineering ,Modeling and Simulation ,Optimal sensor placement ,General Materials Science ,Fatigue damage ,Load reconstruction ,Industrial and Manufacturing Engineering - Abstract
Knowledge of actual wheel-rail contact forces under a service environment is critical for fatigue damage prediction of rail vehicle bogies. This paper presents a method for reconstructing operational wheel loads based on the strain gauge measurements on the bogie of a tram. The strain gauge placement is solved as an optimisation problem, and the actual load–strain relationship is verified by physical calibrations. A novel calibration arrangement is presented to produce linearly independent load cases for a fully equipped bogie. A good correlation of the reconstructed operational stresses with the measured stresses indicated that the identified loads are valid for fatigue assessment. more...
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- 2023
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18. Fatigue damage in fieldshapers used during electromagnetic forming and welding processes at high frequency impulse current.
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Saadouki, B., Sapanathan, T., Pelca, P.H., Elghorba, M., and Rachik, M.
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WELDING , *ELECTROMAGNETISM , *MATERIAL fatigue , *LORENTZ force , *CYCLIC loads - Abstract
Fieldshapers used in electromagnetic forming and welding processes are prone to have fatigue damage. During each test, impulse current passes through the coil that induces an eddy current cycle and a cyclic Lorentz force on the fieldshaper. Thus, the failure of the fieldshapers during service is associated with the cyclic loading conditions during a decaying high frequency electric current pulse. Repetition of the current pulse that causes the damage and eventually results in a failure which is similar to that occurs during a fatigue problem. Therefore, firstly mechanical and fatigue properties of the new material proposed for the fieldshaper (Siclanic alloy) were characterized. Then various fatigue loading cases with input voltages of 6–8.5 kV were investigated to predict the influence of dynamic cyclic loading on the fatigue damage. This study provides a clear understanding of the fatigue damage due to electromagnetic loading and establishes a linear correlation to predict the life cycle for an input electric current. The predicted fatigue damage locations are also in good agreement with the crack formation and their distribution on the filed shapers used in service. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
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19. Fatigue damage assessment using nonlinear critically refracted longitudinal (LCR) wave in pure iron: Experiments and FEM.
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Meng, Yiyuan, Lin, Li, Wang, Yan, Liu, Huahui, and Luo, Zhongbing
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FATIGUE cracks , *IRON , *FATIGUE life , *DISLOCATION structure , *FINITE element method - Abstract
• Nonlinear L CR wave method is proposed to assess early-stage fatigue damage. • The method is non-destructive, thickness-independent, and high-sensitive. • The NLU response mechanism is explained by dislocation string model. • NLU response is corrected based on measured surface roughness. • Nonlinear L CR wave has weaker sensitivity to roughness effect than linear L CR wave. To achieve early-stage microstructure evolution assessment and damage monitoring of fatigue, a new thickness-independent and nondestructive method based on nonlinear critically refracted longitudinal (L CR) wave is proposed. The nonlinear ultrasonic (NLU) parameter is sensitive to the accumulated fatigue damage, showing two peaks around the 5th and 1000th cycles (0.03% and 6% of fatigue life), respectively. This phenomenon is comprehensively discussed in terms of dislocation structure evolution based on the dislocation string model. A correction considering the weakening of nonlinearity induced by the rough surface is applied to the experiment measurements. The corresponding results are closer to the finite element modeling (FEM) quantitation based on the dislocation-dependent nonlinear constitutive relation. Compared to linear L CR wave, nonlinear L CR wave has weaker sensitivity to roughness effect and higher sensitivity to damage such as dislocation, which offers a new method for monitoring fatigue in engineering components. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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20. Investigation of fatigue damage of new-old concrete interface based on piezomagnetic effect.
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Xie, Zhi-Yu, Zhang, Da-Wei, and Wu, Xi
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FATIGUE cracks , *STRAINS & stresses (Mechanics) , *MAGNETIC flux leakage , *CYCLIC loads , *CONCRETE , *ECCENTRIC loads - Abstract
• The relationship between the piezomagnetic signal and interface damage of the new-old concrete interface with shear keys was clarified. • The magneto-mechanical effect, dislocation effect, and magnetic leakage effect during different fatigue stages were explored. • A simulated model of the magnetization of the shear key at the new-old concrete interface was established and validated. Prefabricated concrete structures that employ wet connections create a new-old concrete interface between the pre-cast and cast-in-place layers. To enhance interfacial bonding performance in practical engineering, steel shear keys are frequently employed. The performance of the new-old concrete interface is critical in determining the fatigue performance of prefabricated concrete structures. Therefore, detecting and monitoring interface fatigue damage is essential for the life prediction and damage assessment of the entire structure. This study measured and analysed the piezomagnetic signal of the new-old concrete interface with shear keys under both static and cyclic loads. The piezomagnetic induction intensity was studied based on multiple damage indicators, such as steel strain and interface deformation. The relationship between the piezomagnetic signal and interface fatigue damage was analysed. The magneto-mechanical effect, dislocation effect, and magnetic leakage effect govern the piezomagnetic field change in different fatigue stages. It is found that the piezomagnetic signal exhibits similarities with conventional fatigue damage indicators, undergoing a three-stage variation pattern. Moreover, it demonstrates greater sensitivity to stress loading history and can better reflect the evolution of microstructural defects within the material. Finally, a simulated model of the magnetisation of the shear key at the new-old concrete interface was established and validated. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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21. Fatigue delaminations in composites for wind turbine blades with artificial wrinkle defects.
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Mendonça, Heloisa Guedes, Mikkelsen, Lars Pilgaard, Zhang, Bing, Allegri, Giuliano, and Hallett, Stephen R.
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WIND turbine blades , *MATERIAL fatigue , *FATIGUE cracks , *FATIGUE limit , *WRINKLE patterns , *MANUFACTURING defects - Abstract
Out-of-plane wrinkles are manufacturing defects that affect the structural performance of wind turbine blades under fatigue. Glass Fiber Reinforced Polymer (GFRP) laminated specimens embedded with artificial wrinkle defects at two severity ratios (amplitude/half-wavelength) show different resistance to cyclic loading when tested under tension–compression fatigue. This work presents the validation of a fatigue formulation for the prediction of fatigue damage from wrinkles characteristic of wind turbine blades. The validation is performed through numerical models combined with experimental tests in which the fracture framework aims at predicting crack initiation and delamination propagation. The experimental fatigue program loaded the specimens with R = − 1 to assess damage growth. The fatigue damage mechanism is quantified as a stiffness degradation, and the damage level is classified into five phases. Comparing the two severity types of wrinkles, the fatigue lifetime for equal external loading differs by approximately two decades. This difference is also captured by the numerical predictions. The lower the aspect ratio (AR), the higher the defect resistance to reversed fatigue loading. The numerical models captured the qualitative behavior of the SN curves and delamination fracture path and location observed in the experiments. • Experimental Fatigue behavior of wrinkle defects at two severity types under reversal loading R = − 1. • Modeling framework to assess the defects crack initiation and delamination under fatigue. • SN curves and fracture behavior are predicted for the composite laminates by numerical models. • Fatigue behavior is compared for two defect severity types by experiments and numerical models. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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22. Oxide nodule assisting fatigue crack initiation in hierarchical anisotropic nanostructured Mg-RE alloy.
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Chen, Yao, Shuai, Qi, Wu, Yujuan, Peng, Liming, Shao, Xiaohong, Liu, Fulin, He, Chao, Li, Lang, Liu, Yongjie, Wang, Qingyuan, Xie, Shaoxiong, and Chen, Qiang
- Subjects
- *
CRACK initiation (Fracture mechanics) , *STRUCTURAL reliability , *MAGNESIUM alloys , *ALLOY fatigue , *FATIGUE cracks , *CONSTRUCTION materials , *ALLOYS - Abstract
• A special kind of fatigue damage in the form of scattered oxide nodules. • Hierarchical anisotropic nanostructure leads to the high localization of damage. • LPSO lamellae suppress the growth of the fatigue-induced oxide nodules. Hierarchical anisotropic nanostructured Mg-RE alloys, containing LPSO lamellae and dense nano-precipitates, exhibit superior mechanical properties. However, their reliability as structural materials for long-term service, especially in terms of fatigue, is still a matter of concern. Here, scattered oxide nodules are detected as a special kind of fatigue damage that assists crack initiation, rather than the typical slip-band structure. The LPSO lamellae and dense β′ nano-precipitates lead to the high localization of fatigue damage. The fatigue-induced oxide nodules form and grow within the soft α-Mg layer, but their growth is limited by the adjacent strong LPSO lamellae, resulting in microcrack nucleation. Finally, clusters of microcracks along the LPSO/oxide interface converge to form the trans-granular crack initiation. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
- Full Text
- View/download PDF
23. Off-axis fatigue behaviour of unidirectional laminates based on a microscale fatigue damage model under different stress ratios.
- Author
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Mohammadi, Bijan and Fazlali, Babak
- Subjects
- *
MATERIAL fatigue , *FATIGUE life , *STRAINS & stresses (Mechanics) , *COMPOSITE materials , *FRACTURE mechanics , *MATERIALS compression testing - Abstract
A fatigue damage micro-model is developed for two-phase composite materials. Constitutive law is derived at the level of fibre and matrix and extended for a damaged lamina using the reformulation of Mori-Tanaka model. A new non-dimensional effective local stress based on a failure criterion which is rewritten in term of average stress of fibre and matrix is coupled with a fatigue damage model for prediction of fatigue damage and fatigue life. The proposed model is able to distinguish between damage in fibre and matrix and also stiffness reduction of the matrix and transverse direction during fatigue loading using three different damage variables. The fatigue behaviour of unidirectional carbon/epoxy and glass/epoxy laminates are studied under off-axis loading conditions. Fatigue life of unidirectional composites is predicted at different stress levels, stress ratios and fibre orientations under tension-tension and tension-compression fatigue. The obtained numerical results from the proposed model are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
- Full Text
- View/download PDF
24. An experimental investigation on the shear mechanism of fatigue damage in rock joints under pre-peak cyclic loading condition.
- Author
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Liu, X.R., Kou, M.M., Lu, Y.M., and Liu, Y.Q.
- Subjects
- *
ROCK deformation , *CYCLIC loads , *SHEAR (Mechanics) , *CRACK initiation (Fracture mechanics) , *SHEAR strength - Abstract
In this study, the shear mechanism of fatigue damage in rock joints with first-order and second-order triangular asperities under pre-peak cyclic loading conditions is investigated in laboratory. A monotonic shear test is firstly conducted to determine the shear strength in rock samples containing joints with different orders of asperities. Secondly, influence of the pre-peak cyclic loading conditions with various numbers of cycles on the shear mechanism of fatigue damage in rock joints is studied at constant normal stress. In the cyclic loading conditions, two consecutive steps, such as load-controlled and displacement-controlled, are applied in tests. The load-controlled step is used to achieve the cycles of pre-peak loading in shear tests, and the displacement-controlled step is then applied to realize the final failure of rock samples with constant rate of 0.5 mm / min . Moreover, the effects of shear loading rates, numbers of cycle and cyclic shear loading magnitude on fatigue damage, peak shear strength and residual shear strength of rock joints are researched. We found that fatigue damage occurs at the second-order asperities in the upper and lower blocks within low number of cycles, but the fatigue cracks initiated with initiation angle of 90 ° with respect to the first-order asperities in the upper and lower blocks coalesce with each other (or rock joints) within the high number of cycles. Meanwhile, the variations of peak shear strength and residual shear strength of rock joints within low number of cycles are also different from ones within the high number of cycles. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
- Full Text
- View/download PDF
25. Non-stationarity index in vibration fatigue: Theoretical and experimental research.
- Author
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Capponi, Lorenzo, Cianetti, Filippo, Česnik, Martin, Slavič, Janko, and Boltežar, Miha
- Subjects
- *
MATERIAL fatigue , *RESONANCE , *STRUCTURAL dynamics , *STRAINS & stresses (Mechanics) , *GAUSSIAN function , *KURTOSIS - Abstract
Random vibrations induce damage in structures, especially when they are operating close to their natural frequencies. The stationarity of the input excitation is one of the fundamental assumptions required for frequency-domain fatigue-damage theory. However, for real applications, excitation is frequently non-stationary and the identification of this non-stationarity is not easy. This study researches run-tests to identify the index of non-stationarity. Further, using excitation signals with different rates of amplitude-modulated non-stationarity, the index of non-stationarity is experimentally and theoretically researched with regards to the fatigue life. The experimental research was performed on a flexible structure that was excited close to a natural frequency. The experimental fatigue life is compared to the theoretical fatigue life under the stationarity assumption. The analysis of the experimental results reveals a close relation between the identified non-stationarity in the excitation signal and the fatigue life of the structure. It was found that amplitude-modulated non-stationary excitation results in a significantly shorter fatigue life if compared to a similar level of stationary excitation. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
26. Comparative assessment of remnant tensile properties of modified 9Cr-1Mo steel under prior low cycle fatigue and creep-fatigue interaction loading.
- Author
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Mariappan, K., Shankar, Vani, Sandhya, R., Bhaduri, A.K., and Laha, K.
- Subjects
- *
CYCLIC loads , *MATERIAL fatigue , *FATIGUE crack growth , *FATIGUE cracks , *CRACK initiation (Fracture mechanics) , *STRAINS & stresses (Mechanics) , *STRENGTH of materials - Abstract
Progressive deterioration in the mechanical properties with increasing service period is commonly observed and hence needs to be addressed. Awareness about the rate of degradation of the properties can circumvent a lot of problems faced during service. Hence the present work aims to understand the degradation of tensile properties due to prior cyclic loading. Systematic comparative evaluation study for the evolution of tensile properties with prior fatigue loading and the deformation and damage evolution process in modified 9Cr-1Mo steel during low cycle fatigue (LCF) and creep-fatigue interaction (CFI) loadings has been carried out. For this, LCF and CFI experiments were carried out at constant strain amplitude of ±0.6%, strain rate of 3 × 10 −3 s −1 and temperature of 600 °C. Experiments interrupted after 5, 10, 30, and 50% of the total fatigue life (N f ) under both LCF and CFI conditions were followed by monotonic loading at the same strain rate and temperature until fracture. Drastic reduction in the yield strength value due to both LCF and CFI prior fatigue loading was revealed and the extent of decrease in the YS values increased with the extent of prior fatigue damage imparted on the steel. Substantial difference in the YS evolution with prior fatigue damage under LCF and CFI conditions occurred only after 10% life fraction due to the predominance of creep recovery process. Factors such as microstructural changes due to creep alone or fatigue alone or both and surface oxidation changed the tensile properties under LCF and CFI. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
27. Flexural fatigue behavior and damage evolution analysis of aeolian sand concrete under freeze–thaw cycle.
- Author
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Bai, Jianwen, Xu, Rong, Zhao, Yanru, and Shi, Jinna
- Subjects
- *
FREEZE-thaw cycles , *FATIGUE cracks , *FATIGUE life , *CONCRETE fatigue , *CONCRETE , *SAND , *IRON & steel bridges - Abstract
• The flexural fatigue life of aeolian sand concrete is analyzed by using two-parameter Weibull distribution. • The double logarithmic fatigue equations of freeze–thaw-damaged aeolian sand concrete under different failure probabilities are established. • The fatigue damage evolutions of aeolian sand concrete after freeze–thaw cycle are studied. Aeolian sand is abundant and is widely distributed in western China and thus can reduce the project cost, alleviate the consumption of river sand resources, as well as protect the ecological environment in the application of concrete. Concrete structures, such as roads, bridges, and airport runways in northern cold regions, are exposed to the combined action of freeze–thaw cycle and fatigue load, and the damage mechanism is more serious and complex than that under a single factor. In the present study, the flexural fatigue behavior and damage evolution of aeolian sand concrete under freeze–thaw cycles are studied. Results show that freeze–thaw damage aggravates the flexural fatigue failure of concrete with aeolian sand, and the addition of aeolian sand enhances the average fatigue life of concrete after freeze–thaw cycle. The fatigue life of concrete that has aeolian sand content of 100% is improved more significantly than that of concrete with aeolian sand content of 50%. A double logarithmic fatigue equation is established for varying numbers of freeze–thaw cycles and different failure probabilities. Additionally, the course of flexural fatigue strain and fatigue modulus of aeolian sand concrete under freeze–thaw cycle action follows a typical three-stage development course. The effects of freezing and thawing action on fatigue behavior, such as fatigue strain growth, stiffness degradation, stress–strain relationship, and dissipated energy of 50% aeolian sand concrete (ASC50), are more significant, whereas the effects of 50 and 100 freeze–thaw cycles on the fatigue properties of 100% aeolian sand concrete (ASC100) are not evident. The research results are of great significance for the popularization and use of aeolian sand concrete in cold regions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
- Full Text
- View/download PDF
28. Effects of the associated incorporation of steel wool and carbon nanotube on the healing capacity and mechanical performance of an asphalt mixture.
- Author
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Schuster, Luana, Staub de Melo, João Victor, and Villena Del Carpio, Joe Arnaldo
- Subjects
- *
CARBON nanotubes , *SELF-healing materials , *CARBON steel , *FATIGUE limit , *ASPHALT , *MECHANICAL ability , *HEALING - Abstract
• An asphalt mixture was modified with 1% carbon nanotube and 16% steel wool. • The mixture was investigated for healing ability and mechanical performance. • Incorporations reduced the permanent deformation of the asphalt mixture. • Modifications did not cause decrease in the fatigue resistance of the material. • Additions increased the healing capacity of the asphalt mixture. This research aimed to increase the healing capacity and mechanical performance of an asphalt mixture based on the incorporation of two conductive agents at different levels, steel wool in the microstructure and carbon nanotube in the asphalt nanostructure. Two asphalt mixtures were produced: a reference without additions and another modified with 1% carbon nanotube and 16% fiber/steel wool. Furthermore, additions increased the normalized healing/repair of the asphalt mixture by 49.67%. It could be concluded that the associated incorporation of steel wool and carbon nanotube enhances the healing capacity of the asphalt matrix and, consequently, is beneficial for its mechanical performance. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
- Full Text
- View/download PDF
29. Investigation on multiaxial fatigue crack path using polar stress–strain representation.
- Author
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Albinmousa, Jafar
- Subjects
- *
FATIGUE cracks , *FRACTURE mechanics , *CRACK propagation (Fracture mechanics) , *STRAINS & stresses (Mechanics) , *HYSTERESIS - Abstract
Critical plane concept is widely used as the basis for formulating fatigue damage models. Understanding of fatigue crack behavior, initiation and early growth, under cyclic multiaxial loading is essential for fatigue damage analysis and fatigue life predictions. Full stress–strain fields surrounding an infinitesimal element at the gauge section were obtained by transforming cyclic hysteresis loops using plane stress–strain transformation relations. These fields were represented on polar diagrams to show the loci of maximum stresses or strains with respect to the plane orientation. Measured crack paths were superimposed onto polar diagrams to understand the crack growth behavior with respect to stress or strain fields. Cracks were found to initiate at both planes of maximum normal or shear strains. It was found that there might be equal chances for a crack to initiate and grow at different paths. Polar diagrams can be used to determine the likelihood regions where crack could possibly initiate and grow. [ABSTRACT FROM AUTHOR] more...
- Published
- 2016
- Full Text
- View/download PDF
30. Approach for fatigue damage assessment of welded structure considering coupling effect between stress and corrosion.
- Author
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Yang, Shuo, Yang, Hongqi, Liu, Gang, Huang, Yi, and Wang, Lidong
- Subjects
- *
FATIGUE cracks , *WELDED joints , *STRAINS & stresses (Mechanics) , *STEEL corrosion , *ELECTROCHEMISTRY , *MECHANICAL chemistry - Abstract
This paper presents a new approach to assess time-dependent corrosion fatigue damage of welded joint considering the coupling effect between mechanical factor and corrosion factor. The high stress region around weld will accelerate corrosion and be more likely to induce nonuniform corrosion of welded joint. And the effect of loading on corrosion behavior of the steel in NaCl solution was investigated. The synergistic effect between applied elastic stress and chemical attack on Q235 steel was evaluated by electrochemical experiments. A side longitudinal of ship structure is selected as a case study. Time-dependent stress concentration factor of welded joint as a function of corrosion deterioration was analyzed, and the iterative process of stress and corrosion degeneration of plate thickness was used to simulate coupling effect basing on the results of experiment. The hot spot stress approach was adopted to calculate the fatigue damage. It is revealed that the nonuniform corrosion could influence fatigue damage of welded joint, and that impact will be more and more significant with the growth of corrosion year. [ABSTRACT FROM AUTHOR] more...
- Published
- 2016
- Full Text
- View/download PDF
31. Deformation mechanism and fatigue life of an Al-12Si alloy at different temperatures and strain rates
- Author
-
Hanqin Liu, Z.F. Zhang, J.C. Pang, S.X. Li, Ming-Shan Wang, and Chunlong Zou
- Subjects
Void (astronomy) ,Materials science ,Mechanical Engineering ,Alloy ,Fatigue damage ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,Cracking ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Deformation mechanism ,Mechanics of Materials ,Modeling and Simulation ,engineering ,General Materials Science ,Composite material ,Dislocation ,0210 nano-technology - Abstract
The low-cycle fatigue (LCF) deformation mechanism and fatigue life of an Al-12Si alloy were investigated at different temperatures and strain rates. With increasing temperature, the fatigue life increases at first and then reduces, which is derived from the deformation mechanism. At the lower temperatures, the primary Si cracking induced by piling-up of dislocations dominates fatigue damage behaviors. Both of increasing temperature and reducing the strain-rate can restrain the phase cracking, thus increase fatigue life. However, with further increasing temperature, the micro-scale void caused by dislocation annihilation dominates the phase debonding behavior, leading to the decrease of fatigue life. more...
- Published
- 2019
- Full Text
- View/download PDF
32. Thermo-mechanical fatigue life prediction method under multiaxial variable amplitude loading
- Author
-
Dao-Hang Li, De-Guang Shang, Wang Jinjie, Yu-Juan Sun, and Li Luojin
- Subjects
Materials science ,Mechanical Engineering ,Modulus ,Fatigue damage ,Industrial and Manufacturing Engineering ,Superalloy ,Amplitude ,Creep ,Mechanics of Materials ,Modeling and Simulation ,General Materials Science ,Composite material ,Cycle count ,Constant (mathematics) ,Thermo-mechanical fatigue - Abstract
Based on the Wang-Brown method, a time-dependent multiaxial cycle counting algorithm was proposed under multiaxial thermomechanical variable amplitude loading. By using the proposed multiaxial cycle counting algorithm, a new thermo-mechanical fatigue life prediction method was proposed, in which the pure fatigue damage, creep damage, and the interaction damage taking into account the interaction modulus varying with temperature were calculated for each reversal counted by the cycle counting algorithm. Three types of damage from all the counted reversals for the whole strain-time history were accumulated, and the thermo-mechanical multiaxial fatigue life can be predicted. The thermo-mechanical fatigue experimental data for thin-walled tubular specimen of superalloy GH4169 under multiaxial constant amplitude and variable amplitude loadings were used to verify the proposed method. The results demonstrated that the proposed method can provide very satisfactory prediction results. more...
- Published
- 2019
- Full Text
- View/download PDF
33. Enhanced assessment rule for concrete fatigue under compression considering the nonlinear effect of loading sequence
- Author
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Rostislav Chudoba, Abedulgader Baktheer, and Josef Hegger
- Subjects
Sequence ,Calibration and validation ,Materials science ,business.industry ,Mechanical Engineering ,Fatigue damage ,02 engineering and technology ,Structural engineering ,Tensile strain ,021001 nanoscience & nanotechnology ,Compression (physics) ,Industrial and Manufacturing Engineering ,Nonlinear system ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Cyclic loading ,General Materials Science ,0210 nano-technology ,business - Abstract
In this paper, a refined engineering rule for the assessment of remaining fatigue life of concrete under compressive cyclic loading with varying amplitudes is proposed. The rule has been derived based on a combined numerical and experimental investigation of the loading sequence effect. The applied modeling approach is based on a damage model using the equivalent tensile strain rate to govern the fatigue damage evolution upon loading and reloading at subcritical load levels. A systematic calibration and validation procedure of the numerical model was performed based on the available experimental results. The prediction of the numerical model was compared with existing damage accumulation rules for the assessment of the concrete fatigue life exposed to varying loading ranges. Based on these studies, an enhancement of the Palmgren-Miner rule is proposed and validated for several loading sequence scenarios. more...
- Published
- 2019
- Full Text
- View/download PDF
34. Applying fracture mechanics to fatigue strength determination – Some basic considerations
- Author
-
Michael Vormwald, Mauro Madia, and Uwe Zerbst
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Butt welding ,Fracture mechanics ,Fatigue damage ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,Fatigue limit ,Industrial and Manufacturing Engineering ,Fatigue crack propagation ,Crack closure ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Crack size ,General Materials Science ,Deformation (engineering) ,0210 nano-technology ,business - Abstract
A discussion is provided on demands that must be met in order to apply fracture mechanics to the determination of overall fatigue lifetime and strength, i.e., S-N curves and fatigue limits. These comprise the determination of the cyclic crack driving force for all stages of fatigue crack propagation, in particular for the short crack stage where the crack driving force has to be determined for elastic-plastic deformation and the gradual build-up of the crack closure phenomenon. Special emphasis is put on a fatigue damage relevant specification of the initial crack size. Different approaches in the literature are discussed. Another important aspect is the adequate treatment of multiple crack propagation. Finally, the discussion is illustrated by an example of a butt weld made of a medium strength steel. more...
- Published
- 2019
- Full Text
- View/download PDF
35. Fatigue damage effect approach by artificial neural network
- Author
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Moises Jimenez-Martinez and Mariel Alfaro-Ponce
- Subjects
Chassis ,Materials science ,Artificial neural network ,business.industry ,Mechanical Engineering ,Bracket ,Fatigue damage ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,Fatigue limit ,Industrial and Manufacturing Engineering ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Operating temperature ,Mechanics of Materials ,Modeling and Simulation ,Fracture (geology) ,General Materials Science ,0210 nano-technology ,business ,Constant (mathematics) - Abstract
This study is concerned with the fatigue strength behaviour of chassis components made of steel S420MC. Experimental results show differences when applying sequences of loads, but also when the effect of the operating temperature is taken into account for the prediction of the fracture in the component. Artificial neural networks are a suitable way to establish a relationship between the sequence effects and the fatigue life. To achieve this, the artificial neural network was trained to predict the damage on a rear axle-mounting bracket. Experimental tests were developed at constant and variable amplitudes, defined as load sequences. A series of experimental tests was performed with temperatures of 23 ° C (room temperature), 35 ° C and 45 ° C to evaluate their effect with the different load sequences. Although the maximum temperature used in the experimental set up was only 3 % of the melting temperature, differences in the damage to the component were found. The artificial neural network was trained and validated with 68 experimental results to predict the damage of different loading sequences. The artificial neural network demonstrated a higher prediction capability at some load sequences in comparison to the damage rule. more...
- Published
- 2019
- Full Text
- View/download PDF
36. A numerical study of crack shielding/anti-shielding in layered architectures
- Author
-
Andreu Laborda, Richard Cook, Songsong Lu, Philippa Reed, Yi Zhang, and Rolandas Verbickas
- Subjects
Materials science ,Computer simulation ,Field (physics) ,business.industry ,Mechanical Engineering ,Fatigue testing ,Fracture mechanics ,Fatigue damage ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Electromagnetic shielding ,General Materials Science ,0210 nano-technology ,business ,Parametric statistics - Abstract
Previous research has indicated the potential effectiveness of adopting micro-scale layered architectures to improve the fatigue damage resistance of coatings. However, the optimisation of these coatings is difficult due to the existence of many different factors affecting fatigue performance in such micro-scale layered architectures. In particular, the interaction of successive shielding and anti-shielding processes on crack growth resistance is therefore addressed in this paper by numerical simulation analysis. The crack tip fields in a series of layered architectures were simulated based on varying assumed constitutive materials properties to reveal the interaction of shielding/anti-shielding characteristics in complex architectures in a simple exemplar system. The evolution of crack driving force (CDF) with crack length was calculated and linked to fatigue crack life under relatively simple conditions, including straight crack path and Paris law assumptions, to investigate the effect of the ordering of shielding/anti-shielding characteristics on the crack tip field and hence on fatigue crack life. Layered architectures with different numbers, ordering and placing of layers, were assessed and parametric studies of 4 layered architectures were carried out. This allows analysis of the effect of these individual factors on shielding and their interactive effect with anti-shielding in multi-layered architectures. Understanding the combined effect on crack growth performance and overall fatigue life controlled by crack propagation provides insight into the generic design of micro-scale layered architectures. more...
- Published
- 2019
- Full Text
- View/download PDF
37. Fatigue evaluation for high-speed railway axles with surface scratch
- Author
-
Xishu Wang, Shengchuan Wu, and Zhongwei Xu
- Subjects
Surface (mathematics) ,Materials science ,business.industry ,Mechanical Engineering ,Bending fatigue ,Fatigue damage ,02 engineering and technology ,Structural engineering ,021001 nanoscience & nanotechnology ,Fatigue limit ,Industrial and Manufacturing Engineering ,Axle ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Scratch ,Operation safety ,Modeling and Simulation ,General Materials Science ,0210 nano-technology ,business ,computer ,computer.programming_language - Abstract
With the development of high-speed railway, researchers pay much attention to the fatigue damage evaluation of critical components. For high-speed railway axles, surface scratches are defined as a main defect. The maximum scratch depth was detected carefully about 128 μm based on EA4T axles. To reveal the negative effect of surface scratches on fatigue performance of EA4T steel, rotating bending fatigue texts were carried out. The results indicated that the critical scratch depth (x0) of EA4T steel is about 10 μm. Less than 10 μm, surface scratch has no obvious effect on fatigue performance of EA4T steel. In addition, to evaluate the operation safety of scratch-affected axles, the geometry and loading type effects were considered. The fatigue limit curve of scratch-affected axles was estimated by Murakami equation. A fatigue estimation method of scratch-affected axles was proposed based on three-dimensional Kitagawa-Takahashi diagram that can be used in the maintenance and evaluation of damaged high-speed railway axles. more...
- Published
- 2019
- Full Text
- View/download PDF
38. Effects of pre-fatigue damage on high-cycle fatigue behavior and chloride permeability of RC beams
- Author
-
Wuman Zhang, Bo Diao, Jianchao Xu, Jieqiong Wu, and Runxiao Zhang
- Subjects
Materials science ,Mechanical Engineering ,Static strength ,Fatigue testing ,Fatigue damage ,02 engineering and technology ,Chloride corrosion ,021001 nanoscience & nanotechnology ,Chloride ,Industrial and Manufacturing Engineering ,Chloride permeability ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Fatigue loading ,medicine ,General Materials Science ,Composite material ,0210 nano-technology ,medicine.drug - Abstract
High cycle fatigue behaviors (crack widths, deflections and fatigue life) and chloride permeability of RC beams were experimentally investigated. The experiment processes included initial fatigue loading followed by 3 months of NaCl solution wet-dry cycles without loading, and then fatigue life tests before chloride content measurement. The loading levels (ratio of the maximum fatigue loads over the ultimate static strength) and initial fatigue loading cycles are taken as parameters in this study. Results show that: (1) the fatigue behaviors of RC beams are greatly affected by the loading level and chloride corrosion, but they are rarely influenced by the initial fatigue loading cycles; (2) chloride content markedly increase when the loading levels exceed 0.3; (3) at the loading levels of 0.4 and 0.45, combined actions of initial fatigue damage and chloride corrosion cause at least 13% decrease of the total fatigue life; (4) initial fatigue loading cycles barely affect the residual fatigue life of RC beams when initial fatigue damage of RC beams are in the slow variation stage of damage development. more...
- Published
- 2019
- Full Text
- View/download PDF
39. Fracture evolution in concrete compressive fatigue experiments based on X-ray micro-CT images
- Author
-
Ireneusz Marzec, Jacek Tejchman, and Ł. Skarżyński
- Subjects
Materials science ,Mechanical Engineering ,X-ray ,Uniaxial compression ,Fatigue damage ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,Cracking ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,Fracture (geology) ,General Materials Science ,Tomography ,Composite material ,0210 nano-technology ,Micro ct ,Volume (compression) - Abstract
This study examines the fatigue performance of plain concrete specimens under uniaxial compression. The experimental program was developed for investigating the fracture evolution in concrete cubic specimens subjected to cyclic compression using the advanced X-ray micro-computed tomography system SkyScan 1173. As compared to other experiments, the 3D micro-CT damage images were shown for a various number of loading cycles. The quantitative evolution of the cracking volume with increasing fatigue damage revealed a strongly non-linear shape. The increase of the total crack volume was higher by 30% as compared to the monotonic fatigue test. more...
- Published
- 2019
- Full Text
- View/download PDF
40. Energy-based method of fatigue damage cumulation
- Author
-
Stanisław Mroziński
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Alloy ,Fatigue damage ,02 engineering and technology ,Structural engineering ,engineering.material ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,020303 mechanical engineering & transports ,Amplitude ,0203 mechanical engineering ,Mechanics of Materials ,Modeling and Simulation ,visual_art ,Energy based ,engineering ,Aluminium alloy ,visual_art.visual_art_medium ,Hardening (metallurgy) ,General Materials Science ,0210 nano-technology ,business - Abstract
The study presents the results of low-cycle fatigue tests on AW-2024 aluminium alloy specimens under constant amplitude and multistage loading conditions. As expected, significant hardening of the material was observed in both cases. The tests confirmed that cyclic properties of AW-2024 alloy under multistage loading conditions can be represented based on the results of tests under constant amplitude conditions for the same alloy. The basis for a new fatigue damage cumulation method was formulated based on a comparative analysis of the test results. The main feature of the proposed method consists in including into the analysis the cyclic hardening of AW-2024 alloy during fatigue life calculation. An experimental verification of the method proved its practical applicability. A comparative analysis of the results for a standard Palmgren-Miner hypothesis and the new approach demonstrated the advantages of using the new method. more...
- Published
- 2019
- Full Text
- View/download PDF
41. Fatigue crack initiation and subsequent crack growth in fillet welded steel joints
- Author
-
Tom Lassen and Zbigniew Mikulski
- Subjects
Materials science ,Carbon steel ,Mechanical Engineering ,Monte Carlo method ,Fatigue testing ,Fatigue damage ,Fracture mechanics ,02 engineering and technology ,Welding ,engineering.material ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,law.invention ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,law ,Modeling and Simulation ,engineering ,General Materials Science ,Composite material ,0210 nano-technology ,Fillet (mechanics) ,Stress intensity factor - Abstract
The fatigue damage evolution in fillet welded steel joints where cracks are emanating from the weld toe is investigated. Based on existing experimental data for as-welded joints including crack depth measurements of the early crack growth it is proposed to make a distinction between the crack initiation phase and the subsequent crack growth phase. The welded detail in question is an F class detail with plate thickness 25 mm made of medium strength carbon steel. It is found that the crack initiation phase defined at a crack depth of 0.1 mm is close to 25% of the fatigue life even at a relatively high constant stress range of 150 MPa. At lower stress ranges it is concluded that the initiation phase is the dominating part of the fatigue life. The present work is focusing on the crack propagation phase that is defined from a crack depth of 0.1 mm to final failure of the detail. It is demonstrated that the recommendation given in rules and recommendations (DNVGL and BS 7910) for applying Linear Elastic Fracture Mechanics (LEFM) for the crack propagation phase is valid for the propagation of such small surface breaking cracks. A model based on the rule-based formulas for the Stress Intensity Factor Range (SIFR) and the growth parameters C and m in Paris law agree well the with the measured crack growth curves. For these small semi-elliptical cracks at the weld toe notch important topics like the existence of a threshold limit for the SIFR and the influence of the stress ratio R are discussed. Due to the inherent scatter in the variables characterizing the fatigue damage evolution stochastic approaches are applied for the analyses. Observations and measurements are presented by descriptive statistics and simulations are carried out using Monte Carlo techniques. more...
- Published
- 2019
- Full Text
- View/download PDF
42. Evaluation of fatigue damage of a railhead using an indentation test, acoustic methods and microstructural observations.
- Author
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Kucharski, Stanisław, Mackiewicz, Sławomir, Katz, Tomasz, Starzyński, Grzegorz, Ranachowski, Zbigniew, and Woźniacka, Stefania
- Subjects
- *
FATIGUE cracks , *SERVICE life , *ULTRASONIC measurement , *ELASTIC modulus , *ULTRASONIC testing , *FATIGUE (Physiology) - Abstract
• Local mechanical properties and microstructures of used and unused sides of the railhead (R260 steel) were examined after a certain service life. • Ultrasonic tests and indentation tests at the macro-scale revealed a moderate inhomogeneity of the railhead material. • The fatigue damage was estimated from the deterioration of the elastic modulus and from the plastic work evolution in cyclic indentation tests. • Differences in fatigue damage and microstructure of the examined areas are related to the loading history. The paper presents an investigation of the railhead steel R260. Brinell hardness was measured, spherical microindentation tests were performed and the microstructure was analysed using optical microscopy and SEM images. Fatigue damage in various near-surface regions of the railhead was estimated on the basis of local deterioration of elastic modulus and the development of plastic work in cyclic microindentation tests. There is a clear difference in hardness and fatigue damage between the used and the virgin regions of the railhead. The Brinell hardness and ultrasonic measurements show a change in material properties due to rail manufacturing process. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
- Full Text
- View/download PDF
43. Research on the fatigue magnetization of ferromagnetic materials under low cycle fatigue based on the magneto-mechanical effect.
- Author
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Hu, Xiangyi, Zhao, He, Bu, Yang, Yu, Luchuan, and Zhang, Jianhua
- Subjects
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FERROMAGNETIC materials , *FATIGUE cracks , *MATERIAL fatigue , *MAGNETIZATION , *NONDESTRUCTIVE testing , *VISCOPLASTICITY , *CONCRETE fatigue - Abstract
• A new nonlinear magneto-mechanical model that has superior prediction capability is proposed. • The evolution of the magnetic signal during the fatigue process is obtained. • The relation between magnetic signal and fatigue number is discussed. • The relation between fatigue damage and magnetic signal is proposed. Fatigue damage that caused by low cycle fatigue may lead to many seriously industrial accidents and economic losses, which can be effectively evaluated by magnetic signal based on the magneto-mechanical model. However, the prevailing theoretical model have some limitations (e.g. inaccurate quantification, many unknown coefficients that difficult to obtain, etc.) in describing fatigue magnetization. A new nonlinear magneto-mechanical model based on J-A model proposed in this paper has superior prediction capability for the magnetization under elasto-plastic deformation. In addition, the evolution of the magnetic signal of ferromagnetic materials during the fatigue process is obtained by combining the viscoplastic model and magneto-mechanical model, the fitting equation of magnetic signal and fatigue damage in material fatigue process are proposed, and the determination coefficients are all greater than 0.99. The results of this paper can provide a basis for the electromagnetic nondestructive evaluation of fatigue damage of ferromagnetic materials in engineering. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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44. Addressing the healing compensation on fatigue damage of asphalt binder using TSH and LASH tests.
- Author
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Wang, Chao, Gong, Guanyu, and Ren, Zhengyang
- Subjects
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FATIGUE cracks , *STRAINS & stresses (Mechanics) , *ASPHALT , *STRAIN energy , *REST periods , *HEALING - Abstract
• The damage healing and local life compensation are interactively analyzed. • The energy evolution is well correlated to the damage healing recovery. • A new energy-based parameter (Q H) is proposed for binder healing characterization. This paper investigated the damage healing, local life compensation and intrinsic healing characteristics of asphalt binder. The damage healing (Δ S) is independent of damage level and the percent local life compensation (%Δ N) increases with a higher strain amplitude in TSH test. The integrated Δ S -Δ N analysis is recommended for the healing compensation characterization. The totally stored pseudo strain energy (PSE) to counteract healing recovery is linearly linked to the Δ S regardless of the loading modes, strain amplitudes and rest periods. A new parameter of average stored PSE (Q H) is proposed to reveal the intrinsic healing potential and characteristics. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
- Full Text
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45. Innovative computational modeling of multiaxial fatigue analysis for notched components.
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Ince, A. and Glinka, G.
- Subjects
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FATIGUE life , *MECHANICAL properties of condensed matter , *STRAINS & stresses (Mechanics) , *DEFORMATIONS (Mechanics) , *MATHEMATICAL models , *NUMERICAL analysis - Abstract
Most of the notched components for ground vehicles experience complex multiaxial loadings, where principal stresses rotate and change non-proportionally their magnitudes during a loading cycle. Furthermore, many vehicle components contain notches and geometrical irregularities because of design requirements. These geometric discontinuities cause significant stress concentrations. Multiaxial loads result in complex stress and strain responses at notch areas and can induce a fatigue failure even without any warning of noticeable plastic deformation. Unfortunately, the combination of multiaxial loading paths and complex geometries of mechanical components is unavoidable in practice and experiments performing durability test for ground vehicles are often not feasible because of time and cost considerations. Therefore, an innovative computational fatigue analysis methodology has been proposed here for multiaxial fatigue life analysis of notched components under design process using analytical and numerical methods. The proposed multiaxial fatigue analysis methodology consists of an elastic–plastic stress–strain model and a multiaxial fatigue damage parameter. Computed results of the proposed methodology are compared to sets of experimental published data to verify the prediction capability of the elastic–plastic stress–strain model and the fatigue damage parameter. A comparison of analysis results and experimental data shows that the multiaxial elastic–plastic stress–strain model correlates well with experimental strain data for SAE 1070 steel notched bars subjected to complex non-proportional load paths. The proposed fatigue damage parameter correlates well with fatigue data of 1045 steel and Inconel 718 tubular specimens under proportional and non-proportional loadings. Finally the complete analysis methodology incorporating both the elastic–plastic stress–strain model and the multiaxial fatigue damage parameter is found to be in a good agreement with experimental data of SAE 1045 steel notched shafts subjected to proportional and non-proportional loadings. [ABSTRACT FROM AUTHOR] more...
- Published
- 2016
- Full Text
- View/download PDF
46. 4D evaluation of grain shape and fatigue damage of individual grains in polycrystalline alloys by diffraction contrast tomography using ultrabright synchrotron radiation.
- Author
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Shiozawa, D., Nakai, Y., Miura, R., Masada, N., Matsuda, S., and Nakao, R.
- Subjects
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TENSILE tests , *FATIGUE life , *POLYCRYSTALS , *ALLOYS , *DISLOCATION structure , *X-ray diffraction , *SYNCHROTRON radiation , *ACQUISITION of data - Abstract
A three dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8 ( S uper P hoton ring – 8 GeV), which is the brightest synchrotron radiation facility in Japan, and the measurement conditions and data acquisition procedure are discussed. The developed technique was applied to a commercially pure aluminum, commercially pure iron, and austenitic stainless steel. The shape and location of grains could be determined by DCT using the apparatus in a bending beam line of SPring-8. To evaluate the dislocation structure in tensile tests and fatigue tests, the rotation angle spread of individual grains was measured. The rotation angle spread is caused by mosaicity, which is related to the dislocation structure in a grain. The rotation angle spread was found to increase with increasing plastic strain. Fatigue damage could also be evaluated from the rotation angle spread obtained by DCT measurement. [ABSTRACT FROM AUTHOR] more...
- Published
- 2016
- Full Text
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47. Low cycle fatigue damage and critical crack length affecting loss of fracture ductility.
- Author
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Murakami, Yukitaka, Ferdous, Md. Shafiul, and Makabe, Chobin
- Subjects
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FATIGUE cracks , *DUCTILITY , *FRACTURE mechanics , *FATIGUE life , *SURFACE cracks , *BULK solids , *CRACK initiation (Fracture mechanics) - Abstract
The role of small cracks on fatigue life and loss of ductility are discussed to understand the reality of fatigue damage in low cycle fatigue. The series of low cycle fatigue tests were carried out paying attention to the role of small cracks and their influence on ductility loss. These tests showed that the fatigue lives were pronouncedly extended by removing surface cracks. Also, it was quantified that the loss of fracture ductility was correlated with crack length but not with the number of fatigue cycles. From those results, it is concluded that the behavior of small cracks is crucial to explain the mechanism of low cycle fatigue damage rather than the crack initiation process and change in bulk material properties. [ABSTRACT FROM AUTHOR] more...
- Published
- 2016
- Full Text
- View/download PDF
48. Fatigue of swollen elastomers.
- Author
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Loo, Mei Sze, Le Cam, Jean-Benoît, Andriyana, Andri, Robin, Eric, and Afifi, Amalina Muhammad
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FATIGUE cracks , *ELASTOMERS , *DIESEL fuels , *FIELD emission electron microscopy , *NITRILE rubber , *ENERGY security , *CRACK initiation (Fracture mechanics) - Abstract
The compatibility of the properties of elastomer with conventional diesel fuel has made it favourable in many engineering applications. However, due to global energy insecurity issues, there is an urgent need to find alternative renewable sources of energy as replacements to conventional diesel. In this respect, biodiesel appears to be a promising candidate. Hence, research into the compatibility and fatigue characteristics of elastomers exposed to biodiesel becomes essential. The present paper introduces the first attempt to investigate the effect of different solvents on the fatigue of swollen elastomers. The filled nitrile rubbers are immersed in the palm biodiesel and conventional diesel to obtain the same degree of swelling prior to the application of uniaxial fatigue loading. Field Emission Scanning Electron Microscopy (FESEM) analysis is carried out to observe the fracture surfaces. Stretch-N curves are plotted to illustrate the fatigue life duration. These curves showed that the fatigue lifetime of rubber is the longest for dry rubber and the least for rubber swollen in biodiesel. FESEM micrographs reveal that the loading conditions have no effect on the crack initiation and propagation patterns regardless of the swelling state. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
- Full Text
- View/download PDF
49. A review of fatigue damage assessment in offshore wind turbine support structure.
- Author
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Haselibozchaloee, Danial, Correia, José, Mendes, P., de Jesus, Abilio, and Berto, F.
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FATIGUE cracks , *STEEL fatigue , *WIND turbines , *MECHANICAL behavior of materials , *OFFSHORE structures , *LINEAR statistical models , *FRACTURE mechanics - Abstract
• Nonlinear fatigue accumulation. • Time- and frequency domains. • Shape functions. • Multiaxial fatigue. According to the climate crisis, offshore wind turbines can play an important role to improve the green energy sector. Due to the rough and stochastic metocean environment, the fatigue existence in marine structures is inevitable. Several probabilities and artificial intelligence models can predict the metocean environment for fatigue assessment. Fatigue analysis can be done in time and frequency domains, and for enhancing the efficiency and speed of computation the hybrid model is proposed. Furthermore, the multivariate linear statistical models of the simplified fatigue are also fast with high accuracy. For the Fracture Mechanics method, the geometry functions would be very useful to approximate the fatigue crake growth rate. Besides, J-integral is a criterion to determine the orientation and along with of the fatigue crack and define the plastic behavior of the fatigue crack tip zone. In the local scale, UniGrow and SWT probability models could bring proper fatigue lifetime approximation and recognize the fatigue resistance and residual fatigue. Multiaxial fatigue also can consider the effect of the in- and out-of-phase loading effects through the critical plane method. Furthermore, a survey of the specific offshore steel shows that the fatigue lifetime does not have good agreement with the S-N curve of guidelines due to the inhomogeneity of the material and different mechanical properties. The PhyBal method was used to reduce the cost of the fatigue test and improve the fatigue approximation accuracy. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
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50. Fatigue crack initiation and crystallographic growth in 316L stainless steel.
- Author
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Sistaninia, M. and Niffenegger, M.
- Subjects
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CRACK initiation (Fracture mechanics) , *STAINLESS steel fatigue , *CRYSTALLOGRAPHY , *CRYSTAL growth , *STRESS-strain curves , *HYSTERESIS , *AUSTENITIC stainless steel - Abstract
A mesoscale model of fatigue crack formation and stress–strain behavior in crystalline alloys entitled Sistaninia–Niffenegger Fatigue (SNF) model is applied to AISI 316L austenitic stainless steel. An inelastic hysteresis energy criterion in conjunction with continuum damage modeling provides a strong tool for studying the behavior of the austenitic steel under cyclic loading. The model predictions are validated against fatigue experimental data. The results show that this microstructural-based modeling approach is capable for predicting the behavior of the steel even under complex loading conditions. It can reproduce and help to understand well known fatigue experimental facts, e.g. the effect of grain size and initial defects, by considering the anisotropic behavior of crystalline materials at the level of the microstructure. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
- Full Text
- View/download PDF
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