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The T-shaped deep mixing column (TDM) is a new proposed technique used to increase the ultimate load of the deep mixing column in loose sand. Enlarging the column diameter at a certain depth provides additional bearing area beneath the column under the enlarged part, which leads to an increase in the ultimate load. In this study, a series of laboratory tests were conducted to study and analyse the behaviour of stiffened deep cement mixing columns in loose sand under compression loading. The impact of different parameters such as stiffening methods, embedment ratio, TDM cap length ratio, TDM cap diameter ratio, and the position of the T-shape were studied. It is found that all stiffening methods significantly enhance the load-settlement response of the deep cement mixing (DCM) columns. The stiffening technique of reinforcement bars with a T-shape gives the greatest improvement, increasing the ultimate load by 191.1% compared with the conventional column. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lighter automotive components are needed to reduce energy consumption. The manufacturing processes of the components should also consume less energy and be environmentally friendly. Aluminum is a lightweight material, but the manufacturing processes consume a lot of energy. Ductile iron has outstanding design flexibility and applying a thin wall casting technique to the ductile iron components will reduce the weight and make it possible for ductile iron to compete with lightweight materials. The achievement of making a 3 mm I-beam thickness connecting rod which fulfills the design requirement in previous research has encouraged a further reduction in the I-beam thickness. This action is taken to enhance the weight reduction gained from the connecting rod. The aims of this work are to ensure the repeatability resulting from the design of 3 mm I-beam thickness and the ability of the casting design to produce the 2 mm I-beam thickness. Solidification rates in thin wall casting are critical due to the differences in thicknesses in the product. It is also to analyze the effect of I-beam thickness on the compression load. Two types of I-beams, which differ in their thickness, 3 mm and 2 mm, were produced in the foundry scale. All the I-beams were characterized by their microstructure and compression load. The compression load was measured using the tensile method. The results of microstructure observations revealed that the microstructure in I-beam is different from the one in the end rod except for one casting position, while the result of compression load shows a similar value for average compression load between the 3 mm and 2 mm which fulfill the compression load requirement of connecting rod. The casting designs built in this research can produce thin wall ductile iron (TWDI) connecting rods that could stand similar load with the original one.

Lighter automotive components are needed to reduce energy consumption. The manufacturing processes of the components should also consume less energy and be environmentally friendly. Aluminum is a lightweight material, but the manufacturing processes consume a lot of energy. Ductile iron has outstanding design flexibility and applying a thin wall casting technique to the ductile iron components will reduce the weight and make it possible for ductile iron to compete with lightweight materials. The achievement of making a 3 mm I-beam thickness connecting rod which fulfills the design requirement in previous research has encouraged a further reduction in the I-beam thickness. This action is taken to enhance the weight reduction gained from the connecting rod. The aims of this work are to ensure the repeatability resulting from the design of 3 mm I-beam thickness and the ability of the casting design to produce the 2 mm I-beam thickness. Solidification rates in thin wall casting are critical due to the differences in thicknesses in the product. It is also to analyze the effect of I-beam thickness on the compression load. Two types of I-beams, which differ in their thickness, 3 mm and 2 mm, were produced in the foundry scale. All the I-beams were characterized by their microstructure and compression load. The compression load was measured using the tensile method. The results of microstructure observations revealed that the microstructure in I-beam is different from the one in the end rod except for one casting position, while the result of compression load shows a similar value for average compression load between the 3 mm and 2 mm which fulfill the compression load requirement of connecting rod. The casting designs built in this research can produce thin wall ductile iron (TWDI) connecting rods that could stand similar load with the original one. [ABSTRACT FROM AUTHOR]

The diffusion of Sulfate ions in concrete is a complex process and affects the performance of concrete. Experiments on the time-dependent distribution of sulfate ions in concrete under the coupling of pressure load, dry-wet circulation, and sulfate attack, and the diffusion coefficient of sulfate ions with various parameters was tested. The applicability of the cellular automata (CA) theory to simulate the diffusion of sulfate ions was discussed. In this paper, a multiparameter cellular automata (MPCA) model was developed to simulate the impacts of load, immersion ways, and sulfate solution concentration for the diffusion of sulfate ions in concrete. The MPCA model was compared with experimental data, considering compressive stress, sulfate solution concentration, and other parameters. The numerical simulations verify the calculation results based on the MPCA model are in good agreement with the test data. Finally, the applicability of the established MPCA model was also discussed.

This study presents an innovative design for a cold-formed steel polyurethane (CFS-PU) composite wall panel, combining a cold-formed steel frame, a polyurethane foam infill, and a gypsum fibreboard sheathing. The foam filling process, in which the foam is injected under pressure, ensures uniform distribution, bonding, and interaction of all panel components. The aim of the study is to evaluate the behaviour of the CFS-PU composite panels and the influence of the PU foam and sheathing on the performance of the CFS frame structure. For this purpose, a comprehensive test programme was conducted with nine full-scale specimens, including four CFS-F specimens without infill and sheathing and five CFS-PU specimens with infill and sheathing on both sides. The study examined various aspects of the specimens, including failure modes, stability, stiffness, load-bearing capacity, and ductility index. By analysing these parameters, valuable insights were gained into the performance characteristics of the composite wall panels. The load-bearing capacity of the CFS-PU test specimens was improved by 2.34 times and the stiffness by 1.47 times compared to the CFS-F test specimens. The positive results highlight the potential of foam and sheathing in improving the axial compression performance of CFS walls. [ABSTRACT FROM AUTHOR]

Background and Objectives: In this study, we aimed to compare the physical properties of hole-implantable collamer lenses (H-ICLs) and implantable phakic contact lenses (IPCLs) and investigate their flexural and cell adhesion characteristics. Materials and Methods: Transverse compression load to achieve lens flexion and static Young's modulus were measured in H-ICLs and IPCLs using designated equipment. Load was measured both with and without restraining the optic section of the lenses. Adhesion of iHLEC-NY2 cells to the lens surfaces was examined using phase-contrast microscopy, and cell proliferation activity was evaluated using WST-8 assay. Results: The H-ICL showed a greater tendency for transverse compression load compared to IPCL, while the IPCL showed a higher Young's modulus with respect to the force exerted on the center of the anterior surface of the optic section. The joint between the optic section and haptic support in the IPCL was found to mitigate the effects of transverse compression load. Both lens types showed minimal cell adhesion. Conclusions: Our findings indicate that H-ICLs and IPCLs exhibit distinct physical properties and adhesive characteristics. The IPCL demonstrated higher Young's modulus and unique structural features, while the H-ICL required greater transverse compression load to achieve the flexion required to tuck the haptic supports into place behind the iris to fix the lens. The observed cell non-adhesive properties for both lens types are promising in terms of reducing complications related to cell adhesion. However, further investigation and long-term observation of IPCL are warranted to assess its stability and potential impact on the iris. These findings contribute to a better understanding of the performance and potential applications of H-ICLs and IPCLs in ophthalmology. [ABSTRACT FROM AUTHOR]

To use the laminated composite plates efficiently, it is necessary to develop appropriate analysis theories to predict accurately their structural and dynamical behavior. The analysis of the behavior of the laminated plates is an active research area because of their complex behavior. The structural instability becomes an important concern in a reliable design of composite plates. The majority of the investigations on laminated plates utilize either the classical lamination plate theory (CLPT), or the first-order shear deformation theory (FSDT). Various geometries of the plates subjected to compressive load are studied. The present work deals about a buckling analysis of simply supported symmetric composite plate with four layers. It is assumed that composite plate is surrounded by external elastic fundation. Composite plate is modeled by the finite element method and subjected to biaxial compression load. Governing equations are derived based on Classical Laminated Plate Theory (CLPT) and computed critical buckling loads were compared with numerical results. [ABSTRACT FROM AUTHOR]

The use of cement is expected to increase over the years as the infrastructure continues to develop, and the needs to repair or rehabilitate an old and deteriorated building are necessary. However, many investigations have been conducted to establish promising polymer concrete applications in the last few decades. Meanwhile, using concrete in the construction industry has led to environmental issues. It is because relying on cement production in concrete will contribute to about 7% of the world’s carbon dioxide emissions. Therefore, polymer concrete was introduced in this study to minimise the use of cement in the industry. This research investigated the influence of different amounts of polypropylene (PP) fibre content on polymer concrete (PC) properties by determining the compressive strength, flexural strength and indirect tensile strength. Furthermore, the results of PC failure characteristics have been discussed. The polymer concrete specimens in this study have been cast into cylinders and prismatic specimens using PVC pipe and plywood formwork to determine the compressive strength, splitting tensile strength and flexural strength. By reinforcing PP fibre in the polymer concrete with a specific percentage of fibre reinforced, the overall strength of the polymer concrete was improved. Based on the compressive, splitting tensile, and flexural test results, it has been hypothesised that the 0.16% PP fibre will considerably improve polymer concrete. Additionally, PP fibre maintains a moisture content of less than 0.5% in the aggregates, resulting in a significant enhancement in the mechanical properties of polymer concrete. [ABSTRACT FROM AUTHOR]

Bearing walls in cold-formed steel buildings act as a transmitter of vertical loads of the building and as a retainer of the exterior of the building and also absorb the lateral loads of the building such as wind and earthquake loads. In this article, the behaviour of cold-formed steel frame walls under compressive axial load has been investigated numerically. First, the finite element model of the cold-formed steel wall was developed using ABAQUS software, and then, structural analysis was performed, taking into account the effects of geometric and materials nonlinearities. The results of the numerical model were compared with the experimental results to confirm the accuracy of the numerical model. In the following, parametric studies have been carried out considering some parameters affecting the behavior and the ultimate load of cold-formed steel frame walls such as type of sheathing, stud web depth, stud flange width and stud cross-section shape. The results of the structural analysis showed that the type of wall sheathing did not have a significant effect on the ultimate load of the wall, but increasing the web depth of the stud, has led to a decrease in the load-bearing capacity of the steel wall. The wall with hollow flange studs has a higher ultimate load than other sections, and also, the use of web stiffened stud leads to an increase in the final bearing capacity of the wall compared to typical sections. [ABSTRACT FROM AUTHOR]

To use the laminated composite plates efficiently, it is necessary to develop appropriate analysis theories to predict accurately their structural and dynamical behavior. The analysis of the behavior of the laminated plates is an active research area because of their complex behavior. The structural instability becomes an important concern in a reliable design of composite plates. The majority of the investigations on laminated plates utilize either the classical lamination plate theory (CLPT), or the firstorder shear deformation theory (FSDT). Various geometries of the plates subjected to compressive load are studied. The present work deals about a buckling analysis of simply supported symmetric composite plate with four layers. It is assumed that composite plate is surrounded by external elastic fundation. Composite plate is modeled by the finite element method and subjected to biaxial compression load. Governing equations are derived based on Classical Laminated Plate Theory (CLPT) and computed critical buckling loads were compared with numerical results. [ABSTRACT FROM AUTHOR]

This study presents an innovative design for a cold-formed steel polyurethane (CFS-PU) composite wall panel, combining a cold-formed steel frame, a polyurethane foam infill, and a gypsum fibreboard sheathing. The foam filling process, in which the foam is injected under pressure, ensures uniform distribution, bonding, and interaction of all panel components. The aim of the study is to evaluate the behaviour of the CFS-PU composite panels and the influence of the PU foam and sheathing on the performance of the CFS frame structure. For this purpose, a comprehensive test programme was conducted with nine full-scale specimens, including four CFS-F specimens without infill and sheathing and five CFS-PU specimens with infill and sheathing on both sides. The study examined various aspects of the specimens, including failure modes, stability, stiffness, load-bearing capacity, and ductility index. By analysing these parameters, valuable insights were gained into the performance characteristics of the composite wall panels. The load-bearing capacity of the CFS-PU test specimens was improved by 2.34 times and the stiffness by 1.47 times compared to the CFS-F test specimens. The positive results highlight the potential of foam and sheathing in improving the axial compression performance of CFS walls.

Background and Objectives: In this study, we aimed to compare the physical properties of hole-implantable collamer lenses (H-ICLs) and implantable phakic contact lenses (IPCLs) and investigate their flexural and cell adhesion characteristics. Materials and Methods: Transverse compression load to achieve lens flexion and static Young’s modulus were measured in H-ICLs and IPCLs using designated equipment. Load was measured both with and without restraining the optic section of the lenses. Adhesion of iHLEC-NY2 cells to the lens surfaces was examined using phase-contrast microscopy, and cell proliferation activity was evaluated using WST-8 assay. Results: The H-ICL showed a greater tendency for transverse compression load compared to IPCL, while the IPCL showed a higher Young’s modulus with respect to the force exerted on the center of the anterior surface of the optic section. The joint between the optic section and haptic support in the IPCL was found to mitigate the effects of transverse compression load. Both lens types showed minimal cell adhesion. Conclusions: Our findings indicate that H-ICLs and IPCLs exhibit distinct physical properties and adhesive characteristics. The IPCL demonstrated higher Young’s modulus and unique structural features, while the H-ICL required greater transverse compression load to achieve the flexion required to tuck the haptic supports into place behind the iris to fix the lens. The observed cell non-adhesive properties for both lens types are promising in terms of reducing complications related to cell adhesion. However, further investigation and long-term observation of IPCL are warranted to assess its stability and potential impact on the iris. These findings contribute to a better understanding of the performance and potential applications of H-ICLs and IPCLs in ophthalmology.

The Concrete Filled Steel Tube Column (CFST) is classified as a composite structural element. This type of column was adopted as the main loaded member in many buildings due to its excellent mechanical properties. CFST columns have high strength and ductility behavior, and they can sustain heavy loads with high performance. These led to their adoption in many countries. In the current study, the behavior and strength of CFST columns under the effect of axial compression load with parameters such as the diameter to thickness ratio and the height to diameter ratio were investigated. Strength carrying capacity and axial and lateral deformations with axial and lateral strains were explored. The test results showed that smaller heights within the same material gave higher strength capacity. The stiffness of the CFST is more than concrete and hollow steel section specimens' due to its capability of high strength capacity with low displacement. Also, the composite action of CFST gave more stiffness. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to evaluate the mechanical resistance of elastodontic devices (ED): their maximum compression loads and plastic deformation under loading (percentage). An Instron universal machine (Model 3365, Instron, Industrial Product Group, Grove City, PA, USA) was employed with a 100 N load cell and with Bluehill software for loading analyses. Each device was submitted to a five-cycles test. The following ED were evaluated: A.M.C.O.P. (Micerium, Genova, Italy) in red color, in orange color, and in blue color; HealthyStart (Ortho-Tain, Winnetka, IL, USA), and T4K™ phase 1 (Myofunctional Research Co., Helensvale, Australia). During the five-cycles test, the Ortho-Tain device delivered the greatest compression load (7.56 N), with the lowest percentage of deformation (0.95%). For all devices, a slight plastic deformation of the material was registered, ranging from 0.95% to 1.75%. For the T4K device it was not possible to complete the five-cycles test. For all the analyzed ED, a slight plastic deformation under loading was registered, that in all cases can be considered clinically acceptable. Further studies are needed to test the appliances after clinical usage. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymer(CFRP)is widely used in the design of aircraft fuselage panel.It is important to study the buckling and failure characteristics of panel to improve the efficiency of structural design.The compression buckling load,failure mode and failure load of composite capstringer stiffened panel under compression load are studied by engineering analysis,finite element analysis and panel test.The buckling modes and loads of panels under compression are studied by engineering method and finite element method.The loading capacity of the panel under compression load is studied by the column instability method modified by Von Karman method.Based on the advanced multiload panel test rig,the 3m×2m panel test are completed under compression load and pressure load.The engineering analysis method and finite element analysis method are verified and modified by test.T he results show that the engineering analysis and finite element method need to be modified in buckling analysis,and the results of the modified column instability method are slightly conservative than the test results.

Abstract The problem of this paper is the high contact stress at the point of contact between the cam and the follower. A pear cam and roller follower mechanism were studied and analyzed for different position of the follower and different contact compression load. The objective of this paper is to study the effect of contact compression load on the contact stress distribution of the cam profile at the point of contact. Four different positions of the follower with the cam was considered (0°, 90°, 180°, and 270°). The theory of circular plate was applied to derive the analytic solution of the contact stress. The numerical simulation had been done using ANSYS Ver. 19.2 package to determine the contact stress, while SolidWorks software was used to investigate follower displacement, velocity, and acceleration. Four distinct values of the compression contact load, such as 3.121 N, 6.242 N, 9.364 N, and 12.485 N, were used in the numerical simulation. In the experiment setup, a photo-elastic technique was carried out in the field of polarized light to exhibit the stress distribution on the cam specimen. The annealed PSM-4 backalate material was used in the experiment setup. The experimental value of contact stress was checked and verified analytically and numerically at the point of contact. The innovation in this paper the use of spring-damper system which reduce the value of contact stress at the point of contact. The contact stress was maximum 2.136 MPa when the follower located at 270° with the cam, while the contact stress was minimum 1.802 MPa when the follower located at 180° at compression load 12.485 N.

A solid tire model for forklift trucks has been developed in order to investigate tire performance while supporting a compressive load. The rubber compounds used for solid tire layers were tested to obtain their stress-strain characteristics and to assess applicability of a constitutive model. The Ogden model was suitable for representing the stress-strain characteristics in all layers of a solid tire. The three-dimensional finite element model of a solid tire was developed by assembling the internal, middle, and tread layers. In order to validate this solid tire model, compression load tests were performed on simulated solid tires. The deflection and footprint results of the simulations were found to agree well with experimental data, with an average error less than 10.31%.

Hollow concrete columns are often employed in bridge constructions because of their lighter weight and effective section characteristics. In addition, to reduce the issue of steel reinforcement corrosion and create a strong and light construction, hollow section columns are also reinforced with bars made of fiber-reinforced polymer. This research aimed to analyze the effect of GFRP (glass fiber reinforced polymer) on the compression strength of hollow square concrete columns under an axial concentric load. The finite element application ABAQUS 2019 version was used to simulate a finite element model, calibrated utilizing experimental data from previous studies for various geometric models of concrete and material specifications of the reinforcement. The findings of the experimental studies and the finite element model exhibit excellent agreement. Finally, according to the parametric study's results, A parametric analysis is done to assess the impact of changing reinforcement ratio, spacing between the ties, inner-to-outer section width ratio, and a comparison with steel reinforcement. The computational results clearly show how an Increased longitudinal GFRP reinforcement ratio improves the columns' bearing capability, but when compared to steel reinforcement, it provides less bearing capability. For the optimum outcome with hollow square concrete columns, it is advised to adopt the limit of the i/o between 0.27 and 0.38. In addition, changing the spacing between stirrups was shown not to significantly impact the capacity for axial load in hollow square concrete columns.

Aircraft composites structures are typically made using stiffened skin construction as it provides a minimum weight solution to many design problems. However, designers are reluctant to allow composite stiffened structures to operate in the post-buckled load regimes due to their poor inter-laminar properties. The post-buckling response of cocured composite stiffened panels is explored by experiments and numerical simulations. An integrated progressive damage finite element model is presented which captures inter and intra-laminar failures in panels. Detailed analysis of measured experimental structural responses in terms of strain, deformations, the failure mode is carried out and validated from the numerical analysis. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to evaluate the mechanical resistance of elastodontic devices (ED): their maximum compression loads and plastic deformation under loading (percentage). An Instron universal machine (Model 3365, Instron, Industrial Product Group, Grove City, PA, USA) was employed with a 100 N load cell and with Bluehill software for loading analyses. Each device was submitted to a five-cycles test. The following ED were evaluated: A.M.C.O.P. (Micerium, Genova, Italy) in red color, in orange color, and in blue color; HealthyStart (Ortho-Tain, Winnetka, IL, USA), and T4K™ phase 1 (Myofunctional Research Co., Helensvale, Australia). During the five-cycles test, the Ortho-Tain device delivered the greatest compression load (7.56 N), with the lowest percentage of deformation (0.95%). For all devices, a slight plastic deformation of the material was registered, ranging from 0.95% to 1.75%. For the T4K device it was not possible to complete the five-cycles test. For all the analyzed ED, a slight plastic deformation under loading was registered, that in all cases can be considered clinically acceptable. Further studies are needed to test the appliances after clinical usage.

The problem of this paper is the high contact stress at the point of contact between the cam and the follower. A pear cam and roller follower mechanism were studied and analyzed for different position of the follower and different contact compression load. The objective of this paper is to study the effect of contact compression load on the contact stress distribution of the cam profile at the point of contact. Four different positions of the follower with the cam was considered (0°, 90°, 180°, and 270°). The theory of circular plate was applied to derive the analytic solution of the contact stress. The numerical simulation had been done using ANSYS Ver. 19.2 package to determine the contact stress, while SolidWorks software was used to investigate follower displacement, velocity, and acceleration. Four distinct values of the compression contact load, such as 3.121 N, 6.242 N, 9.364 N, and 12.485 N, were used in the numerical simulation. In the experiment setup, a photo-elastic technique was carried out in the field of polarized light to exhibit the stress distribution on the cam specimen. The annealed PSM-4 backalate material was used in the experiment setup. The experimental value of contact stress was checked and verified analytically and numerically at the point of contact. The innovation in this paper the use of spring-damper system which reduce the value of contact stress at the point of contact. The contact stress was maximum 2.136 MPa when the follower located at 270° with the cam, while the contact stress was minimum 1.802 MPa when the follower located at 180° at compression load 12.485 N. [ABSTRACT FROM AUTHOR]

The present study investigates the increasing in ultimate pile capacity and studied the soil plugging phenomenon and the incremental filing ratio for a modified type of open-ended pipe pile. The modification performed by adding steel plates as wings with special dimensions and fixed on the exterior face of the pipe pile wall at a location near the pile tip with specified dimensions. Five wings have used for each new model of pipe pile. These wings distributed in equal spacing along with the circumstances of the exterior wall of the open-ended pipe piles. The efficiency of the proposed type studied by modelling and manufacturing twelve piles (40 mm diameter, L/D = 15 and L/D = 20). Complete setup manufactured for installing and loading the piles in a constant rate of penetration. The model piles installed in poorly graded loose dry sand. The obtained results show that the proposed type has a higher ultimate bearing capacity. The percentage of increase reaches more than 50%. The development of the load capacity is due to the three effects. The first is increases of the exterior shaft friction, and the second effect creates a new end-bearing capacity under the constrained soil between the exterior wings. And the third effect is developing the end-bearing capacity under the soil plug inside open-ended pipe pile due to the first and the second effects. [ABSTRACT FROM AUTHOR]

A solid tire model for forklift trucks has been developed in order to investigate tire performance while supporting a compressive load. The rubber compounds used for solid tire layers were tested to obtain their stress-strain characteristics and to assess applicability of a constitutive model. The Ogden model was suitable for representing the stress-strain characteristics in all layers of a solid tire. The three-dimensional finite element model of a solid tire was developed by assembling the internal, middle, and tread layers. In order to validate this solid tire model, compression load tests were performed on simulated solid tires. The deflection and footprint results of the simulations were found to agree well with experimental data, with an average error less than 10.31%. [ABSTRACT FROM AUTHOR]

Brazing joints of Ti/Ti under ultrasonic vibration (USV) and compression load were investigated using optimized and modified filler alloys of Al-Si-Cu-(Ni)-(Sr) group prepared in the lab. Preliminary trails at semisolid to liquid states were conducted using the ready Al-Si-Cu-(Mg) alloy as a filler, then the brazing cycle was redesigned and enhanced according to the microstructural observations of the produced joints. USV assisted brazing at the semisolid state of low solid fraction was able to produce joints with round silicon morphology and granular α−Al, while at a high solid fraction, USV was only able to affect the silicon and intermetallic particles. Applying a compression load after ultrasonic vibration, at a designed solid fraction, was proved to be a successful technique for improving the quality of the joints by reducing the porosity, enhancing the soundness of the joint, and the diffusion at the interface. Based on alloy composition and the improved brazing cycle, joints of thin intermetallic layer and high shear strength (of 93 MPa average value) were achieved. The microstructures and the mechanical behavior were discussed based on the filler compositions and brazing parameters.

In this paper, experimental studies on two laminated composite hat-stiffened panels with equally spaced stiffeners have been carried out with application of axial compression load on the panel for the determination of the pre-buckling and post buckling behavior. A non-linear buckling analysis on the hat-stiffened panel has also been performed under compression load with application of finite element tool ABAQUS. From strain analysis at different locations, the local buckling of skin has been observed before the buckling of the panel, and a visual damage has been found near the skin-stiffener and debonding skin-stiffener of the panel during failure of the hat-stiffened panel. The compression load-axial displacement curve of the experiments has correlated well with simulated finite element model result for determination of the buckling behavior of the panel up to the failure load. The out of plane displacement pattern shows that the compressive failure initiated at the edges of the panel and gone to skin-stiffener bonding, and finally failure of the panel occurred due to debonding between skin-stiffener. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cartilage tissue engineering repair is an important method to repair cartilage defects. Silk fibroin/type II collagen scaffolds are viscoelastic materials that have excellent biocompatibility and exhibit solid and liquid characteristics, but the micro-mechanical properties between different layers are still a problem worthy of attention. OBJECTIVE: To obtain the relationship between macro-loading force of scaffold and micro-force between layers, so as to obtain the macro-force under the micro-force of optimal cell proliferation. METHODS: The compression stress relaxation experiment of the blank scaffold was designed, and the finite element model of the scaffold was constructed after fitting viscoelastic constitutive equation with experimental data. The stress relaxation of the model was simulated to obtain the mechanical state between the scaffold layers. RESULTS AND DISCUSSION: The force of each layer of the scaffold was distributed at 1.185-3.305 N, and the stress of each layer gradually decreased with time until it converged. The total displacement of the scaffold increased with the number of layers. The strain values between the layers of the scaffold ranged from 1.82x10-2-4.47x10-2 to 4.47x10-2-4.47x10-2. This value indicates that this is the best state for culturing cells. The finite element analysis results show that when 10% strain occurred macroscopically in the scaffold, the strain value of each layer was distributed in the numerical range of 2%-7%. When the macro strain of the stent was 5%, the strain value of each layer was distributed between 1% and 2%. When 20% strain occurred on the scaffold macroscopically, the strain value of each layer was distributed between 8% and 18%. Comparison results revealed the optimal strain value for cell proliferation was 4%-7%. [ABSTRACT FROM AUTHOR]

It is well known that stress-induced phase transformation in dual-phase steel leads to the degradation of bulk corrosion resistance properties. Predicting this behaviour in high carbon steel is imperative for designing this grade of steel for more advanced applications. Dual-phase high carbon steel consists of a martensitic structure with metastable retained austenite which can be transformed to martensite when the required energy is attained, and its usage has increased in the past decade. In this study, insight into the influence of deformed microstructures on corrosion behaviour of dual-phase high carbon steel was investigated. The generation of strain-induced martensite formation (SIMF) by residual stress through plastic deformation, misorientation and substructure formation was comprehensively conducted by EBSD and SEM. Tafel and EIS methods were used to determine corrosion intensity and the effect of corrosion behaviour on hardness properties. As a result of the static compression load, the retained austenite transformed into martensite, which lowered its corrosion rate by 5.79% and increased the dislocation density and the length of high-angle grain boundaries. This study demonstrates that balancing the fraction of the martensite phase in structure and dislocation density, including the length of high-angle grain boundaries, will result in an increase in the corrosion rate in parallel with the applied compression load. [ABSTRACT FROM AUTHOR]

• A new method to simulate variable tangential/normal load conditions. • Under low tangential to normal load ratio, subsurface cracks could be observed. • Under high tangential to normal load ratio, numerous surface cracks could be observed. • Chipping could occur as soon as the surface cracking density is higher than 0.13. The mechanical mating components (e.g., gear teeth and stamping dies) usually have an inclined contact which introduces additional tangential forces and accelerates the formation of the surface fatigue cracking. To study such effects on the surface fatigue behaviours of engineering materials and coatings, an inclined sliding test was adopted to have varying ratios of tangential to normal loads at different positions inside the wear scar during each cyclic loading. In this study, a plasma nitrided ductile cast iron (D6510) was tested under various contact angles, which led to different ratios of tangential to normal loads. The results demonstrated that subsurface cracks occurred at the low ratio while the surface cracks dominated at the high ratio when the inclined sliding contact stresses were very high. Severe surface fatigue failure like chipping could occur as soon as the surface cracking density is higher than 0.13. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of the compressive response of hexagonal honeycomb core from the initial elastic regime to a fully crushed state. To understand the crushing mechanism, aluminum honeycomb core was compressed quasi-statically between rigid platens under displacement control. Honeycomb test specimens made of aluminum alloy with different configurations such as cell size, cell number, core density, and specimen size have been tested. During the crushing, the cells buckle elastically and collapse at a higher stress due to inelastic action, after the cells crush by progressive formation of folds on cell walls. The response densifies when folds consume the whole panel height. The peak load recorded during tests corresponded to the buckling of honeycomb cells. The different specimens showed similar load/displacement curves, and the differences observed were only due to the influence of the core density, number of cells, and specimens size on mechanical behavior of hexagonal honeycomb core which has a very important role in the energy absorption capacity. In addition, this study allowed us to build a database of experimental tests for various configurations and allowed us to know the precise energy absorption capacity. [ABSTRACT FROM AUTHOR]

• Effective thermal conductivity of the Li 2 TiO 3 pebble bed was strongly dependent on a kind of atmospheric gases. • Effective thermal conductivity of the Li 2 TiO 3 pebble bed was not significantly changed by the hydrogen concentration ratio in helium atmosphere within a range of less than 1.0 wt.%. • Applied axial compression load has influenced on the effective thermal conductivity of the Li 2 TiO 3 pebble bed, especially at high temperature. • Obvious change of effective thermal conductivity with the value of compression load until 3 MPa was not observed. Tritium breeder material in the solid-type of breeding blanket concepts is usually used in a pebble bed form because of the efficiency and convenience of tritium extraction. The pebble bed is continuously heated by the exothermal reaction between neutron and lithium-6 during the operation of a fusion reactor. Thus, a compression pressure is applied on the pebble bed by the thermal expansion of pebbles and container structure. Therefore, the accurate thermal properties of the pebble bed are one of the important design parameters to ensure a function and stability of the breeding blanket. This study aims at the investigation of the change on effective thermal conductivity of Li 2 TiO 3 pebble beds under the operation conditions of breeding blanket. The measurement of effective thermal conductivities of Li 2 TiO 3 pebble beds has been performed by laser flash technique in several atmosphere gases, such as helium, nitrogen, and air, under the statically compression load controlled by specially design pneumatic device incorporated to the laser flash apparatus. Also, in the case of helium atmosphere, the effects of hydrogen concentration from 0.1 wt.% to 1.0 wt.% on the effective thermal conductivity were also investigated. The effective thermal conductivity of the Li 2 TiO 3 pebble bed was strongly dependent on a kind of atmosphere gases, especially its thermal conductivity, in the relatively low temperature. However, the concentration of hydrogen in the helium atmosphere did not significantly affect the effective thermal conductivity of the pebble bed. Applied axial compression load has influenced on the effective thermal conductivity of the Li 2 TiO 3 pebble bed, especially at high temperature. However, the obvious change of effective thermal conductivity with the value of compression load was not observed. [ABSTRACT FROM AUTHOR]

This study used liquefied red mud (RM) sludge, an aluminum industry by-product, as a construction material. Accordingly, various methods were examined that used the fabricated liquefied red mud (LRM) as an admixture for concrete, and the mechanical properties of concrete were then evaluated according to the cement type and the amount of LRM. The LRM mixing methods (replacement and addition) were compared, and the slump and compressive strengths of concrete were evaluated for each method. To examine the mechanical properties according to the cement type and the amount of LRM, two types of cement (ordinary Portland cement and slag cement (SC)) were used, and 20 and 40 wt% LRM (with respect to the cement weight) were added. The mechanical properties of the stress−strain curve (SSC), compressive strength, peak strain, and elastic modulus were quantified. When the slump and compressive strength of concrete were considered based on the experimental results, the addition LRM mixing method was recommended as the appropriate method for LRM. As the addition of LRM increased, the mechanical properties of concrete degraded. However, when SC was used, the mechanical properties did not significantly change when different amounts of LRM were added (up to 20%). In addition, the SSC of LRM concrete could be approximated based on the use of the relationship of the compressive strength and peak strain according to the cement type and the amount of LRM.

Tests were carried out to determine the bending moment capacities of L-shaped mortise and tenon furniture joints under both compression and tension loadings. The effects of wood species (Turkish beech and Scotch pine), adhesive type (polyvinylacetate and polyurethane), and tenon size (width and length) on the static bending moment capacity of joints under the same loading conditions were investigated. The results of the tests indicated that the moment capacity increased as either tenon width or length increased. The results also indicated that tenon length had a greater effect on the moment capacity than tenon width. In both compression and tension tests, Turkish beech joints were stronger than Scotch pine joints, and PU joints were stronger than PVA joints. An empirically derived expression was developed to estimate the average ultimate bending moment capacity of joints under compression and tension loads as functions of the wood species, the adhesive type, and the tenon size.

Background and aims: Epidemiological studies have shown a significant correlation between awkward back posture and low back pain among carpet weavers. Therefore, this study aims for estimating cumulative compression load among carpet weavers during a shift work. Methods: In this study, the awkward back postures of 4 male and 9 female carpet weavers were monitored, using electronic inclinometer for 4 hours. The level of cumulative compression load for a 8-hour shift was calculated. Results: The highest compression load exerted on L4/L5 was due to the compacting and knotting subtasks. The maximum, cumulative compression load was related to the subtask of weaving. The levels of cumulative compression load during a shift work in male and female groups were estimated equal to 21.8 and 13.13MN-S, respectively. Conclusion: Results showed that although the level of compression load in both gender groups is lower than the recommended limit, the level of cumulative compression load in males is higher than in females. Therefore, results from different studies show that the estimation of compression load, per se, does not suggest the existence of physical stresses on the low back. In addition, the estimation of daily commutative compression can be an important index in predicting occupational low back pain

A typic BLSF ceramics: bismuth titanate (Bi 4 Ti 3 O 12 ), whose failure mode, ferroelastic behavior and toughening effect under uniaxial compression load were comprehensively assessed. Firstly, a series of crystallographic parameters including lattice constants ( a , b , c and v ), orthorhombicity ( g ) and single-crystal distortion ( S 0 lattice ) were calculated from XRD patterns. The ferroelastic behavior referred to the 90° switching of domains with compression stress was identified by the nonlinear stress-strain curve, and the underlying micromechanism was more accurately described by the non-180° domain wall motion. SEM observation on the fracture surface of the broken sample reveals its failure mode in terms of microcrack initiation and propagation behaviors. Further, a simplified domain distribution model was constructed for unpoled ferroelectric ceramics based on a constitutive framework, which deduced their constitutive relation subjected to uniaxial compression load. The ferroelasticity induced toughening was verified by indentation test, and further analyzed by a micromechanics model of crack propagation. The expression of toughening effect (Δ Г / Г ) was also deduced from the indentation fracture mechanics. Finally, the evolution in mechanical properties (including coercive stress ( σ c ), switching strain (ε zz ), apparent elastic modulus ( E ) and compression strength ( σ cf )) of Bi 4 Ti 3 O 12 ceramics with the doping content of W was also quantified by the compression test. [ABSTRACT FROM AUTHOR]

Rigid and semi-rigid fixations are investigated several times in order to compare their biomechanical stability. Interbody fusion techniques are also preferable for maintaining the sagittal balance by protecting the disk height. In this study, the biomechanical comparison of semi-rigid and rigid fixations with posterior lumbar interbody fusion or transforaminal lumbar interbody fusion procedures is conducted under trauma. There were four different test groups to analyze the effect of acute load on treated ovine vertebrae. First and second groups were fixed with polyetheretherketone rods and transforaminal lumbar interbody fusion and posterior lumbar interbody fusion cages, respectively. Third and fourth groups were fixed with titanium rods and posterior lumbar interbody fusion and transforaminal lumbar interbody fusion cages, respectively. The drop tests were conducted with 7 kg weight. There were six samples in each group so the drop test repeated 24 times in total. The test samples were photographed and X-rayed (laterally and anteroposteriorly) before and after drop test. Two fractures were observed on group 1. Conversely, there were no fractures observed for group 2. There were no anterior element fractures for both groups 1 and 2. However, one fracture seen on group 3 was anterior element fracture, whereas the other three were posterior element fractures. All three fractures were anterior element fractures for group 4. Treated vertebrae with polyetheretherketone rods and posterior lumbar interbody fusion cages showed the best durability to the drop tests among the groups. Semi-rigid fixation gave better results than rigid fixation according to failed segments. Posterior lumbar interbody fusion cages seem to be better option for semi-rigid fixation, however mentioned surgical disadvantages must be considered. [ABSTRACT FROM AUTHOR]