45 results on '"Explosive load"'
Search Results
2. Study on Explosion Resistance of a New Type of Prefabricated T-Joint
- Author
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Wang, Yu, Huang, Jincheng, Yue, Haile, di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Cui, Zhen-Dong, Series Editor, Tuns, Ioan, editor, Muntean, Radu, editor, Radu, Dorin, editor, Cazacu, Christiana, editor, and Gălățanu, Teofil, editor more...
- Published
- 2024
- Full Text
- View/download PDF
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3. A Study on Crack Initiation and Propagation of Welded Joints under Explosive Load.
- Author
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Ding, Penglong, Gong, Xuhui, Sun, Lei, Niu, Jiajia, Zhang, Youjing, and Xu, Lianyong
- Subjects
CRACK propagation (Fracture mechanics) ,NOTCHED bar testing ,WELDED joints ,FRACTURE toughness ,EXPLOSIVE welding ,THEORY of wave motion ,STRESS waves ,STRUCTURAL steel ,SURFACE waves (Seismic waves) - Abstract
Welded joints in naval ship hull structures are weak areas under explosive load, but there are relatively few studies investigating the failure characteristics of welded joints through dynamic fracture and explosion tests. In order to explore and predict the failure characteristics of welded joints under explosive load, instrumented Charpy impact tests, explosion tests, and numerical simulations were carried out. The dynamic fracture toughness of ultra-high strength ship hull structural steel welded joints was obtained, and the dynamic stress intensity factors, together with the correlation between stress wave and crack propagation at different positions, were acquired. The results showed that the stress state at the crack tip of a Charpy impact specimen was consistent with that of a welded joint under explosive loads, and the crack initiated when the dynamic stress intensity factor exceeded the dynamic fracture toughness. The results indicated that the dynamic fracture toughness obtained by instrumented Charpy impact tests could be used to predict the crack initiation characteristics of welded structures under explosive load, and the stress wave at the crack tip was basically perpendicular to the crack propagation surface and promoted the rapid propagation of cracks. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
4. Study on the Anti-Progressive Collapse Behavior of Steel Frame Structures under Close-Range Blast Loading.
- Author
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Ke, Changren, Long, Huihui, and Jiang, Junling
- Subjects
STEEL framing ,PROGRESSIVE collapse ,STRUCTURAL frames ,BLAST effect ,STRUCTURAL failures ,COLUMNS ,FINITE element method - Abstract
The steel frame structure plays an important role in strategic deployments and is widely used in heavy machinery, metallurgy, military, and other important industries. To study the impact of explosive loads on the anti-progressive collapse performance of steel structures, this paper proposes to establish the vulnerability characteristics of steel frame structures and provides a method for calculating vulnerability characterization indicators. A finite element model is used to analyze the dynamic response of steel frame structures under the action of close-range explosive loads, and factors influencing the anti-progressive collapse of steel frame structures are proposed, including the number of stories and diagonal bracing. A comparison is made between the various column types of steel structures under explosive loads, such as corner columns, long-edge middle columns, short-edge middle columns, inner columns, also in various coupling conditions. The results show that the progressive collapse of steel frame structures is greatly influenced by the position of the explosion and less affected by the amount of explosive material. The simultaneous failure of corner columns and long-edge middle columns is more likely to cause overall structural failure. The addition of diagonal bracing significantly improves the anti-progressive collapse ability and prevents the lateral displacement of steel frame structures; increasing the number of stories provides more alternative load transfer paths for steel frame structures, thereby preventing their collapse. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
5. Explosion resistance performance of reinforced concrete box girder coated with polyurea: Model test and numerical simulation
- Author
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Guangpan Zhou, Rong Wang, Mingyang Wang, Jianguo Ding, and Yuye Zhang
- Subjects
Explosive load ,Explosion resistance performance ,Model test ,Polyurea ,Concrete box girder ,Numerical simulation ,Military Science - Abstract
To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder, two segmental girder specimens were made at a scale of 1:3, numbered as G (without polyurea coating) and PCG (with polyurea coating). The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests. The reliability of the numerical simulation using LS-DYNA software was verified by the test results. The effects of different scaled distances, reinforcement ratios, concrete strengths, coating thicknesses and ranges of polyurea were studied. The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder. The top plate of middle chamber in specimen G forms an elliptical penetrating hole, while that in specimen PCG only shows a very slight local dent. The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%, respectively, compared with those of specimen G. For the TNT explosion with small equivalent, the polyurea coating has a more significant protective effect on reducing the size of fracture. With the increase of TNT equivalent, the protective effect of polyurea on reducing girder displacement becomes more significant. The optimal reinforcement ratio, concrete strength, thickness and range of polyurea coating were also drawn. more...
- Published
- 2024
- Full Text
- View/download PDF
6. Microscopic defects formation and dynamic mechanical response analysis of Q345 steel plate subjected to explosive load
- Author
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Zhengqing Zhou, Zechen Du, Yulong Zhang, Guili Yang, Ruixiang Wang, Yuzhe Liu, Peize Zhang, Yaxin Zhang, and Xiao Wang
- Subjects
Explosive load ,Q345 steel ,Micro defect ,Finite element simulation ,Dynamic response ,Data fitting ,Military Science - Abstract
As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate under the explosive load and its macroscopic dynamics simulation. Firstly, the defect characteristics of the steel plate were investigated by stereoscopic microscope (SM) and scanning electron microscope (SEM). At the macroscopic level, the defect was the formation of cave which was concentrated in the range of 0–3.0 cm from the explosion center, while at the microscopic level, the cavity and void formation were the typical damage characteristics. It also explains that the difference in defect morphology at different positions was the combining results of high temperature and high pressure. Secondly, the variation rules of mechanical properties of steel plate under explosive load were studied. The Arbitrary Lagrange-Euler (ALE) algorithm and multi-material fluid-structure coupling method were used to simulate the explosion process of steel plate. The accuracy of the method was verified by comparing the deformation of the simulation results with the experimental results, the pressure and stress at different positions on the surface of the steel plate were obtained. The simulation results indicated that the critical pressure causing the plate defects may be approximately 2.01 GPa. On this basis, it was found that the variation rules of surface pressure and microscopic defect area of the Q345 steel plate were strikingly similar, and the corresponding mathematical relationship between them was established. Compared with Monomolecular growth fitting models (MGFM) and Logistic fitting models (LFM), the relationship can be better expressed by cubic polynomial fitting model (CPFM). This paper illustrated that the explosive defect characteristics of metal plate at the microscopic level can be explored by analyzing its macroscopic dynamic mechanical response. more...
- Published
- 2024
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7. Micro defects formation and dynamic response analysis of steel plate of quasi-cracking area subjected to explosive load
- Author
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Zheng-qing Zhou, Ze-chen Du, Xiao Wang, Hui-ling Jiang, Qiang Zhou, Yu-long Zhang, Yu-zhe Liu, and Pei-ze Zhang
- Subjects
Explosive load ,Quasi-cracking area ,Micro defects ,Steel plate ,Dynamic response ,Numerical simulation ,Military Science - Abstract
As the protective component, steel plate had attracted extensive attention because of frequently threats of explosive loads. In this paper, the evolution of microstructure and the mechanism of damage in the quasi-cracking area of steel plate subjected to explosive load were discussed and the relationships between micro defects and dynamic mechanical response were revealed. After the explosion experiment, five observation points were selected equidistant from the quasi-cracking area of the section of the steel plate along the thickness direction, and the characteristics of micro defects at the observation points were analyzed by optical microscope (OM), scanning electron microscope (SEM) and electron back-scattered diffraction (EBSD). The observation result shows that many slip bands (SBs) appeared, and the grain orientation changed obviously in the steel plate, the two were the main damage types of micro defects. In addition, cracks, peeling pits, grooves and other lager micro defects were appeared in the lower area of the plate. The stress parameters of the observation points were obtained through an effective numerical model. The mechanism of damage generation and crack propagation in the quasi-cracking area were clarified by comparing the specific impulse of each observation point with the corresponding micro defects. The result shows that the generation and expansion of micro defects are related to the stress area (i.e. the upper compression area, the neutral plane area, and the lower tension area). The micro defects gather and expand at the grain boundary, and will become macroscopic damage under the continuous action of tensile stress. Besides, the micro defects at the midpoint of the section of the steel plate in the direction away from the explosion center (i.e. the horizontal direction) were also studied. It was found that the specific impulse at these positions were much smaller than that in the thickness direction, the micro defects were only SBs and a few micro cracks, and the those decreased with the increase of the distance from the explosion center. more...
- Published
- 2024
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- View/download PDF
8. Structural Dynamic Response of a Frame Tunnel under Coupled Impact-Explosion Loading.
- Author
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Huang, Zhen, Qin, Maojiang, Zhang, Chenlong, Zhang, Wenjun, and Hu, Zhaojian
- Abstract
As the main structural bodies of underground facilities such as subway stations, frame tunnel structures play an important role in urban development and construction. In recent years, with the frequent occurrence of explosions after vehicle impacts in tunnels, which have caused severe damage to frame tunnels, the lack of relevant papers makes it necessary to develop a dynamic response analysis of frame tunnels. In this paper, by optimizing the design of an original frame tunnel structure, a dynamic response numerical model of the frame tunnel considering the impact effect of a 3D solidified vehicle and the joint effect is investigated. The deformation trend and damage evolution of the frame tunnel are analysed under different collision masses (1.4, 2.4, 6 and 15 t), collision angles (5, 10, 15 and 75°), collision speeds (60, 80 and 100 km/h), blast delay times (10, 20 and 30 ms) and blast equivalents (50, 100 and 200 kg TNT). This paper improves the active and passive robustness of frame tunnels using both improved operational management and the optimal design of the tunnel structure as a way to ensure the structural safety and functional resilience of frame tunnels. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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9. A Study on Crack Initiation and Propagation of Welded Joints under Explosive Load
- Author
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Penglong Ding, Xuhui Gong, Lei Sun, Jiajia Niu, Youjing Zhang, and Lianyong Xu
- Subjects
explosive load ,butt joint ,dynamic fracture toughness ,crack initiation and propagation ,Naval architecture. Shipbuilding. Marine engineering ,VM1-989 ,Oceanography ,GC1-1581 - Abstract
Welded joints in naval ship hull structures are weak areas under explosive load, but there are relatively few studies investigating the failure characteristics of welded joints through dynamic fracture and explosion tests. In order to explore and predict the failure characteristics of welded joints under explosive load, instrumented Charpy impact tests, explosion tests, and numerical simulations were carried out. The dynamic fracture toughness of ultra-high strength ship hull structural steel welded joints was obtained, and the dynamic stress intensity factors, together with the correlation between stress wave and crack propagation at different positions, were acquired. The results showed that the stress state at the crack tip of a Charpy impact specimen was consistent with that of a welded joint under explosive loads, and the crack initiated when the dynamic stress intensity factor exceeded the dynamic fracture toughness. The results indicated that the dynamic fracture toughness obtained by instrumented Charpy impact tests could be used to predict the crack initiation characteristics of welded structures under explosive load, and the stress wave at the crack tip was basically perpendicular to the crack propagation surface and promoted the rapid propagation of cracks. more...
- Published
- 2024
- Full Text
- View/download PDF
10. Study on the Anti-Progressive Collapse Behavior of Steel Frame Structures under Close-Range Blast Loading
- Author
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Changren Ke, Huihui Long, and Junling Jiang
- Subjects
steel frame structure ,dynamic analysis ,explosive load ,progressive collapse ,vulnerability ,Building construction ,TH1-9745 - Abstract
The steel frame structure plays an important role in strategic deployments and is widely used in heavy machinery, metallurgy, military, and other important industries. To study the impact of explosive loads on the anti-progressive collapse performance of steel structures, this paper proposes to establish the vulnerability characteristics of steel frame structures and provides a method for calculating vulnerability characterization indicators. A finite element model is used to analyze the dynamic response of steel frame structures under the action of close-range explosive loads, and factors influencing the anti-progressive collapse of steel frame structures are proposed, including the number of stories and diagonal bracing. A comparison is made between the various column types of steel structures under explosive loads, such as corner columns, long-edge middle columns, short-edge middle columns, inner columns, also in various coupling conditions. The results show that the progressive collapse of steel frame structures is greatly influenced by the position of the explosion and less affected by the amount of explosive material. The simultaneous failure of corner columns and long-edge middle columns is more likely to cause overall structural failure. The addition of diagonal bracing significantly improves the anti-progressive collapse ability and prevents the lateral displacement of steel frame structures; increasing the number of stories provides more alternative load transfer paths for steel frame structures, thereby preventing their collapse. more...
- Published
- 2024
- Full Text
- View/download PDF
11. Reinforced Concrete Matrices Under Impulse Loads
- Author
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Kretov, Dmitriy, di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Akimov, Pavel, editor, and Vatin, Nikolai, editor more...
- Published
- 2022
- Full Text
- View/download PDF
12. Effect of stress waveform on the rock blasting crack propagation mechanism using numerical simulation
- Author
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Yong-qi LI, Zheng-zhao LIANG, Xi-kun QIAN, and Hong-bo LIU
- Subjects
explosive load ,waveform ,prefabricated crack ,rock crack ,three dimensional numerical simulation ,Mining engineering. Metallurgy ,TN1-997 ,Environmental engineering ,TA170-171 - Abstract
The type, proportion, and charging method of explosives produce different stress waveforms, which greatly affect rock crack propagation. Because of the complex interaction law between waveform parameters such as the peak value, wavelength, energy, and rise or fall rate, and the limited physical and mechanical test conditions, quantitatively controlling waveform parameters in a blasting test is difficult. Numerical simulation has advantages in revealing the influence law of the stress wave. In this paper, RFPA3D dynamic analysis software was used to simulate the crack propagation in a rock with a prefabricated crack under impact loads, and the effects of the stress wave peak value, energy, rise rate, and fall rate of the stress wave on the rock crack propagation process were investigated. Results show that the rock crack propagation pattern under dynamic loads was affected by the rise rate of the stress wave. The faster the stress wave rose, the more breakages occurred around the hole. For the crack propagation length, the crack grew longer with the increase in the stress wave energy. When the stress wave energy was constant, the crack grew farther with the decrease in the rise rate, but the broken degree around the hole was decreased. The rise rate and the energy of the rising edge of the stress wave affected the radius of the comminution zone. Numerical simulation results revealed the rock crushing mechanism of different stress wave peak values, energies, and rise or fall rates. In a practical engineering blasting operation, to expand the impact range of blasting, extending the action time using a water cannon mud seal or an air column interval charge structure was suggested. In addition, the appropriate type and proportion of explosives were also selected to increase the stress wave’s rise rate to improve the effect of hole edge crushing. more...
- Published
- 2022
- Full Text
- View/download PDF
13. Implosion mechanisms of metallic cylindrical shells subjected to combined explosive loading and hydrostatic pressure.
- Author
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Huang, Zhixin, Dou, Shuangtao, Ren, Xianben, and Li, Ying
- Subjects
- *
CYLINDRICAL shells , *SUBMERGED structures , *WATER pressure , *IMPLOSIONS , *ALUMINUM alloys , *HYDROSTATIC pressure - Abstract
Underwater hollow structures are always subjected to high hydrostatic pressure and there is a serious risk of implosion. To investigate the effects of exploring the combined explosive loading and hydrostatic pressure on cylindrical shells in a deep water environment. A combination of background, experimental, and numerical simulations is used to investigate the response of aluminum alloy cylindrical shells subjected to impact loading under subcritical buckling pressure. Based on the non-contact underwater explosive load, a pressure tank impact explosion experimental device is designed, and the implosion experiments of cylindrical shells under different explosive intensities are carried out. Based on this simulation analysis, the relationship between the ambient water pressure and the explosive loading and implosion of cylindrical shells is investigated. Results show that at low external hydrostatic pressures, cylindrical shells can be induced to implode by large shock loads, and that different explosive loading leads to changes in the implosion damage pattern of cylindrical shells. Based on the results of the parametric analysis, the implosion boundary map is drawn and the danger level region is summarized. Finally, from the energy perspective, the results show that the internal energy of the shell is combined with the shock strength and hydrostatic pressure, and the relationship is nonlinear. • An experimental device is designed which can be used to explore the combined induced implosion of cylindrical shells by explosive loading and hydrostatic pressure. • An experimental and numerical simulation investigation of metallic cylindrical shells under the combined explosive loading and hydrostatic pressure has been conducted. • Cylindrical shell implosion boundary map is summarized and dangerous region is classified. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
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14. The Explosion Resistance of Double-layer Honeycomb Sandwich Panel Under Blast Load
- Author
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Xiangjiang ZHAO, Xiaomin MA, Shiqiang LI, Lijia XU, and Guiying WU
- Subjects
double-layer gradient sandwich panel ,explosive load ,deformation failure mode ,explosion resistance ,relative density ,Chemical engineering ,TP155-156 ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Technology - Abstract
In order to deeply analyze the influence of core layer size parameters on the anti-explosion performance of sandwich panel under explosive load, on the basis of the fiber-reinforced three-layer honeycomb sandwich structure, the dynamic response of the double-layer gradient sandwich panel made of fiber-reinforced aluminum alloy panel and aluminum alloy honeycomb core layer under explosive load was studied by experiment and numerical simulation. First, the deformation failure modes of the double-layer gradient sandwich panel in the experiment were analyzed: large deformation of the whole sandwich structure, failure of the front panel in the central area and compression buckling of the core layer, and penetration failure of the front panel and the core layer in the central area. Second, the influence of the change in the hole length and wall thickness on the explosion resistance performance of the upper core layer was examined without changing the geometric size of the lower core layer by numerical simulation. The results show that the specimen with the same hole side length of the upper and lower core layer had better explosion resistance performance, and when the density ratio of the upper and lower core layer was 3∶1 while the side length of the upper and lower core layer was the same, the structure had the best anti-explosion performance. more...
- Published
- 2021
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15. An Innovative Failure Criterion for Metal Cylindrical Shells under Explosive Loads.
- Author
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Li, Yan, Wang, Wen, and Chen, Zhanfeng
- Subjects
- *
CYLINDRICAL shells , *METAL fractures , *PRESSURE vessels , *FINITE element method , *IMPACT loads - Abstract
Metal cylindrical shells are widely used to store and transport highly hazardous chemicals. The impact resistance of metal cylindrical shells under an explosive load is a concern for researchers. In this paper, an innovative failure criterion considering the time effect is proposed for metal cylindrical shells under explosive loads. Firstly, based on the maximum shear stress criterion, an innovative failure criterion containing the time effect is provided. Then, a metal cylindrical shell model is established. Next, a failure pressure equation for metal shells under an explosive load is proposed based on the innovative failure criterion. Lastly, the proposed equation is verified by numerical simulation. The results indicate the failure pressure equation for a metal cylindrical shell under an explosive load uses the finite element method. Our research is of significance for fully understanding the failure mechanism of piping and pressure vessels under impact load. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
16. A COMPARISON BETWEEN EXPERIMENTAL AND NUMERICAL STUDIES FOR REINFORCED CONCRETE SLABS UNDER BLAST LOADING.
- Author
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Duy Hoa Pham and Ba Danh Le
- Subjects
BLAST effect ,CONCRETE slabs ,BRITTLE materials ,REINFORCED concrete ,FINITE element method ,CIVIL engineering - Abstract
Explosion is a special load, it rarely happens, but consequences are very serious. Research on the effect of explosive loads on reinforced concrete (RC) slabs is important to reduce unexpected consequences. This research has been an interesting topic in Vietnam during recent years because there have been accidents due to explosive loads in the country. This is the basis for the design of military structures or special buildings in civil engineering in Vietnam. This paper presents experimental and numericalstudies of the fracture response of RC slabs using materials available in Vietnam under blast loading. The concrete slabs with the length of 1000mm, the width of 800mm and the thickness of 120mm are manufactured and tested. The emulsion explosive has been used. Two cylindrical explosive blocks with masses of 0.5kg and 1.22kg are considered. These tests are modeled using the finite element method. Concrete is supposed to be brittle material and follow the Johnson–Holmquist-II (JH-2) model. The steel rebar is modeled following an elasto-plastic model. The emulsion explosive is converted to TNT explosive equivalent and modeled by the SPH method. The concrete crater, spall damage and dynamic behavior of concrete slabs under blast loading are considered. The comparison between experimental and numerical results allows to validate the numerical model to modeling the behavior of our concrete under blast loading. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
17. SIMULATION OF VISCOELASTIC-PLASTIC BEHAVIOR OF SHALLOW SHELLS WITH ACCOUNT FOR STRAIN RATE OF MATERIALS.
- Author
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Yankovskii, A. P.
- Subjects
- *
BOUNDARY value problems , *INITIAL value problems , *PLASTICS , *BLAST waves , *NUMERICAL integration - Abstract
This paper describes a numerical-analytical model of the viscoelastic-plastic behavior of flexible shallow shells with account for the dependence of plastic properties of their materials on strain rate. The inelastic behavior of materials is described by the theory of flow with isotropic hardening. Loading functions depend on the hardening parameter and strain rate intensity. Viscoelastic behavior is described by linear constitutive equations from a multiconstant body model. Transverse shears of structures during bending deformation are taken into account within the framework of the Ambartsumyan theory, and geometric nonlinearity within the von Karman approximation. A cross-type explicit scheme is used for the numerical integration of the formulated initial boundary value problem. The dynamic deformation of a cylindrical elongated panel made of a polymer material is studied. The structure is transversely loaded by a pressure generated by an air blast wave. It is shown that neglecting the dependence between the plastic properties of the material and the strain rate may cause one to significantly underestimate a maximum deflection in absolute value and the largest strain value during oscillations and cause one to overestimate a maximum residual strain. In addition, residual deflection diagrams obtained by such a calculation do not agree with the diagrams obtained by a calculation that takes the mentioned dependence into account. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
18. The Dynamic Caustics Test on the Growth Law of Fractures in Tunnel Surrounding under Explosive Load.
- Author
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Liu, Kang, Guo, Dongming, Zhang, Jun, and Kang, Xinchao
- Subjects
- *
FRACTURE mechanics , *MECHANICAL loads , *TUNNELS , *KINEMATICS , *ENERGY transfer - Published
- 2021
- Full Text
- View/download PDF
19. Postblast damage assessment of concrete-filled double-skin tube columns by intelligence-based techniques.
- Author
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Wang, Xuyue, Li, Tao, Wang, Yuliang, and Xu, Yue
- Subjects
- *
COMPOSITE columns , *CONCRETE-filled tubes , *MACHINE learning , *BLAST effect , *DATABASES - Abstract
This paper aims to use machine learning (ML) based on a regression algorithm to predict the damage degree of a concrete-filled double-skin steel tubular column (CFDST) after explosion. Three classical single learning algorithms and five excellent ensemble learning algorithms were used to train 2476 sets of data. Five regression indicators were used to evaluate and compare the effectiveness and accuracy of the ML model. The results show that the integrated CatBoost model is superior to the other models, and the model performances are ranked as CatBoost > LightGBM > XGBoost > GBDT > MLP > RF > SVR > DT. Shapley Additive exPlanations (SHAP) is used to explain the contribution of each feature parameter to CatBoost prediction results. Finally, the CatBoost model is used to predict the collected test data, and R2 = 0.989, MSE = 2.98 × 10−6, RMSE = 0.00172, MAE = 0.00151, and MAPE = 7.4% are obtained. This shows that the model has high prediction accuracy and can accurately predict the damage degree after CFDST explosion. • An extensive database of CFDST columns subjected to the close-in explosion is established. • Three classical single learning algorithms and five excellent integrated learning algorithms are used to predict the damage degree of concrete-filled double-skin steel tubular column (CFDST) columns under close-in explosion loads. • After model training and evaluation, the CatBoost model has the best accuracy among the eight models. • The global and local interpretation of the CatBoost model is carried out through the Shapley Additive exPlanations(SHAP), and the influence of different input parameters on the model is visualized. • In the actual damage assessment, compared with the problem that the traditional P-I curve regression formula can only obtain the damage degree of the CFDST column, the CatBoost model can obtain accurate damage conditions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
20. Modeling of elastoplastic behavior of flexible spatially reinforced plates under refined theory of bending
- Author
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Andrei Petrovich Yankovskii
- Subjects
composite plate ,spatial-cross reinforcement ,flat-cross reinforcement ,reddy theory ,refined theory of bending ,elastic-plastic deformation ,geometric nonlinearity ,explosive load ,“cross” scheme ,Mathematics ,QA1-939 - Abstract
On the basis of the time-steps algorithm the structural model is constructed for elastic-plastic deformation of bended plates with spatial reinforcement structures. The inelastic behavior of the composition phase materials is described by equations of the theory of plastic flow with isotropic hardening. The possible weakened resistance of the reinforced plates to the transverse shear is taken into account on the basis of the refined theory, from which the relations of the Reddy theory are obtained in the first approximation. The geometric nonlinearity of the problem is considered in the Karman approximation. The solution of the formulated initial boundary value problems is based on an explicit numerical “cross” scheme. The dynamic inelastic deformation of spatially- and flat-cross-reinforced metal-composite and fiberglass flexible plates of different relative thickness is investigated in the case of the load caused by an air blast wave. It is demonstrated that for relatively thick fiberglass plates, the replacement of the flat-cross reinforcement structure by the spatial structure with the preservation of the total fiber consumption leads to a decrease in the structural flexibility in the transverse direction by almost 1.5 times, as well as to a decrease of the maximum of intensity of deformation in the binder by half. For relatively thin both fiberglass and metal-composite plates, the replacement of flat-cross 2D reinforcement structure with 3D and 4D spatial structures does not lead to a noticeable decrease in their deflections, but allows to reduce the intensity of deformations in the binder by 10 % or more. It is shown that the widely used non-classical Reddy theory does not allow obtaining reliable results of calculations of the elastic-plastic dynamic behavior of the bended plates, both with plane and spatial reinforcement structures, even with a small relative thickness of the structures and weak anisotropy of the composition. more...
- Published
- 2019
- Full Text
- View/download PDF
21. Modeling Elasto-Plastic Behavior of Space-Reinforced Flexible Curved Panels Taking into Account Possible Weakened Resistance to Transverse Shears
- Author
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Andrei P. Yankovskii
- Subjects
curved panels ,spatial reinforcement ,reddy theory ,geometric nonlinearity ,elastic-plastic deformation ,explosive load ,“cross” scheme ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
A mathematical model of elastic-plastic behavior of flexible curved panels with spatial reinforcement structures is developed. The inelastic deformation of the composition components is described by the theory of plastic flow with isotropic hardening. The possible weakened resistance of composite panels to transverse shears is taken into account in the framework of the non-classical Reddy theory, and the geometric nonlinearity is considered in the Karman approximation. The solution of the formulated initial-boundary value problem is obtained by an explicit numerical “cross” scheme. The bending inelastic behavior of “flat”- and spatially-reinforced cylindrical panels under the action of dynamic loads of explosive type is investigated. The glass-plastic and metal-composite structures are considered. It is shown that for relatively thick glass-plastic panels (and in some cases for relatively thin ones), the replacement of the flat-cross structure of the reinforcement with the spatial structure leads to a decrease in the deflection of the composite structure by several tens of percent. In cases of metal-composite panels, such replacement of reinforcement structures practically does not lead to a decrease in their flexibility in the transverse direction. more...
- Published
- 2019
22. Modeling the dynamic bending of rigid-plastic fiber-reinforced laminated curvilinear doubly connected thin plates with free outer contour.
- Author
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Romanova, Tatiana Pavlovna
- Subjects
- *
DYNAMIC models , *STRUCTURAL models , *LAMINATED materials , *FIBERS - Abstract
A theoretical model of the dynamic bending of rigid-plastic hybrid composite, arbitrary curvilinear doubly connected thin plates is developed. Inner contour of the plate is simply supported or clamped and outer one is free. The plates are on a viscous basis and under the action of uniformly distributed loads of explosive type. The plates are laminated and fibrous, with layers arranged symmetrically with respect to the middle surface. In each layer the reinforcing fibers, made of different materials, are located in directions parallel or normal to inner contour of plate. The structural model of the reinforced layer considering the plane stress state in fibers is used. The equations of the dynamic deformation of plate and simple analytical formula for the limit load are obtained. Numerical examples are given for a fiber-reinforced four-layered curvilinear plate with a supported hole in the form of ellipse and super-ellipse at the same total amount of reinforcement. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
- Full Text
- View/download PDF
23. A novel method for rapidly calculating explosion dynamic displacement response of reticulated shell structure based on influence surfaces.
- Author
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Xin Chen, Xuanneng Gao, Xiang Lin, Jingliang Liu, and Lihui Le
- Subjects
- *
CYLINDRICAL shells , *EXPLOSIONS - Abstract
In order to analyse the mechanical behaviour of a reticulated shell structure under explosive load, a novel method was proposed to calculate the dynamic displacement response of the cylindrical reticulated shell structure by using the influence surface in this article. First, the theory of the dynamic influence line was developed and the consistency between the dynamic influence lines and the static ones was verified. Then, based on the theory of the dynamic influence line and for the simplified calculation of dynamic responses, the dynamic influence lines of a simply supported beam were simplified as the static ones multiplied by the dynamic amplification factor β. And then the explosion dynamic responses of the beam could be fast calculated using the influence lines. The extended application of the above method to single-layer cylindrical reticulated shell was the influence surface method. The results of numerical examples showed that the nodal displacements of the structure obtained by using the influence surface method agreed well with those obtained by using ANSYS/LS-DYNA. The research results also indicated that the influence surface method was applicable to the node displacement calculation of the structure under three different conditions, including the centre node of the symmetrical structure, the arbitrary nodes (excluding those near the supports) of symmetrical structure under symmetrical loads and the arbitrary nodes of arbitrary structures in which the load holding time is much longer than the natural vibration period of structure. The proposed approach could reduce the computation cost for analysing the explosion dynamic response of the reticulated shell structure, thereby providing a more effective method for the anti-explosion design of reticulated shell structures. [ABSTRACT FROM AUTHOR] more...
- Published
- 2020
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24. Modeling the Dynamic Behavior of Rigid-Plastic Thin Reinforced Curvilinear Plates with a Hole on a Viscous Foundation.
- Author
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Romanova, T. P.
- Subjects
- *
HUMAN behavior models , *DYNAMIC models , *STRUCTURAL models , *GEOSYNTHETICS , *DYNAMIC loads - Abstract
A mathematical model is developed for the dynamic behavior of rigid-plastic thin reinforced layered curvilinear, hinge-supported or clamped, plates with an arbitrary free hole. The plates are on a viscous foundation and are subjected to the action of a dynamic load of explosive type uniformly distributed on its surface. The plates are hybrid, multilayered, and fibrous, with their layers distributed symmetrically with respect to the middle surface. In each layer, the reinforcing fibers are located parallel or normal to the external contour of plate. The structural model of a reinforced layer is used. Depending on intensity of the load, various dynamic deformation modes of the plates are possible. From the principle of virtual power, with account of d'Alembert's principle, the equations of dynamic behavior of the plates are obtained and the conditions for their implementation are determined for each of the modes. Analytical expressions for estimation of their limit loads are obtained. The variant of quasi-isotropic reinforcement is considered. Numerical examples for a reinforced elliptic plate with a circular hole are given. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
- Full Text
- View/download PDF
25. 基于零厚度粘聚力单元的钢筋混凝土板在爆炸荷载下的动态破坏过程分析
- Author
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吴志军, 张鹏林, 刘泉声, 李万峰, and 江维中
- Abstract
Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department 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.) more...
- Published
- 2018
- Full Text
- View/download PDF
26. Effect of Heat Treatment Duration on Interface Characteristics of Explosively Bonded Cu/SS-304 Plates
- Author
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Padash, Ehsan, Khanzadeh, Mohammadreza, Bakhtiari, Hamid, Bakhtiari, Zahra, Shajari, Yazdan, and Seyedraoufi, Zahrasadat
- Published
- 2021
- Full Text
- View/download PDF
27. Modeling the Dynamic Bending of Rigid-Plastic Hybrid Composite Elliptical Plates with a Rigid Insert.
- Author
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Romanova, T.
- Subjects
- *
METALS , *MECHANICAL loads , *DEFLECTION (Mechanics) , *FIBERS , *DEFORMATIONS (Mechanics) - Abstract
A model of dynamic bending of rigid-plastic hybrid composite elliptical plates with a rigid center and simply supported or clamped contour, subjected to a uniformly distributed short-time intense dynamic load of explosive type is developed. The plates are multilayered and fibrous, with a symmetric distribution of layers with respect to the middle surface. The reinforcing fibers, made of different materials, are located in directions parallel or normal to the plate contour. Various mechanisms of dynamic deformation of the plates are considered. For each mechanism, equations of their dynamic behavior are obtained. Operating conditions of these mechanisms are analyzed. Analytical expressions for evaluating the limit loads, deformation time, and residual deflections are obtained. It is shown that a change in reinforcement parameters significantly affects the bearing capacity and residual deflection of the plates. The solutions proposed can be used in the design of reinforced metal-composite elliptical plates. Numerical examples are given for different reinforcement structures. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
28. Damage assessment of marine grade aluminium alloy-plated structures due to air blast and explosive loads.
- Author
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Cerik, Burak Can
- Subjects
- *
ALUMINUM alloys , *AIR blast circuit breakers , *FINITE element method , *FUSION welding , *BLAST effect , *MECHANICAL loads - Abstract
The objective of this paper is to investigate the response of fusion welded AA5083-H116 rectangular plates and orthogonally stiffened panels, typically found in high-speed vessels and topsides of offshore platforms, under impulsive pressure loading, such as air blast and explosions. Rigorous nonlinear finite element analyses are performed by using ABAQUS/Explicit to determine the deformation of these plated-structures under different impulses. Particular emphasis is given on the effect of the heat affected zone (HAZ), which is due to fusion welding. Based on the extensive numerical results, simple yet accurate formulae to predict the permanent set of the plates are derived as function of a non-dimensional impulse parameter. The derived equations are also compared with the existing analytical and empirical formulae in the literature. [ABSTRACT FROM AUTHOR] more...
- Published
- 2017
- Full Text
- View/download PDF
29. Fragment Velocity Distribution of Cylindrical Rings Under Eccentric Point Initiation.
- Author
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Huang, Guangyan, Li, Wei, and Feng, Shunshan
- Subjects
VELOCITY ,EXPLOSIONS ,ELECTROMAGNETIC waves ,X-rays ,IONIZING radiation - Abstract
A design mode, in which a casing is filled with a charge initiated off-centre (eccentric point initiation), is common in the field of explosion and structural protection. The fragment velocity distribution along the circumference of the casing is distinctly non-uniform due to the difference in blast loading around the circumference of the casing. To quantify the fragment velocity distribution, two kinds of cylindrical rings with different structural parameters were adopted. Static explosive experiments with three eccentric coefficients (0, 0.5, 1.0) were conducted with pulsed X-ray diagnostics. Using coefficients derived from experimental data and calculating the effects of both the eccentricity of initiation and angle around the circumference, an angle-dependent ratio β
θ of charge mass to casing mass has been derived as a mean to modify the fragment velocity formula of Gurney for this application. The derived formula was shown to correctly predict the fragment velocity distribution around the circumference of the cylindrical ring. The calculated velocity distributions show good agreement with the experimental results. [ABSTRACT FROM AUTHOR] more...- Published
- 2015
- Full Text
- View/download PDF
30. Contributions of In-Situ Stress Transient Redistribution to Blasting Excavation Damage Zone of Deep Tunnels.
- Author
-
Yan, Peng, Lu, Wen-bo, Chen, Ming, Hu, Ying-guo, Zhou, Chuang-bing, and Wu, Xin-xia
- Subjects
- *
TUNNELS , *EXCAVATION , *STRAINS & stresses (Mechanics) , *MECHANICAL loads , *COMPUTER simulation - Abstract
With the background of construction of the headrace tunnels with the deepest buried depth in China at present, by means of carefully acoustic velocity detection and analysis of Excavation Damage Zone (EDZ), the contributions to damage zones made by the effect of in situ stress transient redistribution are studied and compared with the extent of damage caused by the explosive load. Also, the numerical simulation was adopted to verify detecting the results. It turned out that the in situ stress transient redistribution during blasting has great influence on the development of EDZ of deep tunnels. The blasting excavation-induced damage zone of deep tunnels can be divided into the inner damage zone and the outer damage zone from the excavation surface into surrounding rocks. Although this damage zone dividing method is similar to the work of Martino and Chandler (), the consideration of developing a mechanism of the inner damage zone, especially the contribution of in situ stress transient redistribution, is totally different. The inner damage zone, which accounts for 29-57 % of the total damage zone, is mainly caused by explosive load and in situ stress transient adjustment, while the outer damage zone can be mostly attributed to the static redistribution of in situ stress. Field tests and numerical simulation indicate that the in situ stress transient redistribution effect during blasting contributes about 16-51 % to the inner damage zone in the 2# headrace tunnel of Jinping II Hydropower Station. For general cases, it can be concluded that the in situ stress transient redistribution is one of the main contributors of an excavation damage zone, and damage caused by in situ stress transient redistribution effect may exceed the damage caused by explosion load and become the main inducing factor for damage with the rise of in situ stress levels. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
- Full Text
- View/download PDF
31. An Innovative Failure Criterion for Metal Cylindrical Shells under Explosive Loads
- Author
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Yan Li, Wen Wang, and Zhanfeng Chen
- Subjects
failure criterion ,metal cylindrical shells ,failure pressure ,explosive load ,General Materials Science - Abstract
Metal cylindrical shells are widely used to store and transport highly hazardous chemicals. The impact resistance of metal cylindrical shells under an explosive load is a concern for researchers. In this paper, an innovative failure criterion considering the time effect is proposed for metal cylindrical shells under explosive loads. Firstly, based on the maximum shear stress criterion, an innovative failure criterion containing the time effect is provided. Then, a metal cylindrical shell model is established. Next, a failure pressure equation for metal shells under an explosive load is proposed based on the innovative failure criterion. Lastly, the proposed equation is verified by numerical simulation. The results indicate the failure pressure equation for a metal cylindrical shell under an explosive load uses the finite element method. Our research is of significance for fully understanding the failure mechanism of piping and pressure vessels under impact load. more...
- Published
- 2022
- Full Text
- View/download PDF
32. 1226. Analytical solution for dynamic response of segment lining subjected to explosive loads.
- Author
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Yang Liu, Mingyang Wang, and Derong Wang
- Subjects
- *
DYNAMIC models , *EXPLOSIVES , *MECHANICAL loads , *JOINTS (Engineering) , *STRUCTURAL engineering , *DYNAMICAL systems - Abstract
The existence of various types of joints, one of the typical characteristics of prefabricated lining structures, makes the mechanical performance of shield tunnel linings quite different from that of monolithic linings. A simplified calculation method for the dynamic elastic-plastic analysis of segment lining subjected to explosive loads is proposed. The lining is composed of a number of rigid arch segments that are interconnected by elastic-plastic hinges. The dynamic interaction between the segments and the bolts, and the interaction between tunnel lining segment and soil-structure can be properly simulated with the method. As an example, the calculation of the shield section of Nanjing metro subjected to blast loading was discussed. The time-history curves of displacement and speed of some key points of section lining were obtained. Furthermore, the influences of rock grade and joint stiffness on dynamic response of tunnel lining were taken into account. The result indicates that the simplified method of blasting response analysis can reflect the response of structure subjected to blast loading accurately. The results will be a reference for antiknock analysis and design of tunnel lining. [ABSTRACT FROM AUTHOR] more...
- Published
- 2014
33. Steel square hollow sections subjected to transverse blast loads
- Author
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Jama, H.H., Nurick, G.N., Bambach, M.R., Grzebieta, R.H., and Zhao, X.L.
- Subjects
- *
BLAST effect , *THIN-walled structures , *STEEL , *EXPLOSIVES , *DEFORMATIONS (Mechanics) , *PLASTICS , *CROSS-sectional method - Abstract
Abstract: Thin-walled steel hollow sections are used extensively in the construction, offshore, mining and security industries. Such members subjected to blast loads are of interest due to increased security demands and the occurrence of accidental or intentional explosive events. This paper reports an experimental and analytical investigation of steel square hollow sections subjected to transverse blast load, applied with explosive uniformly distributed along the length of the member. Three different section sizes were tested over three different lengths, and the members were fully clamped at their ends. The explosive loads were sufficient in magnitude to cause plastic deformation of the cross-section (local deformation), plastic flexural deformation of the overall member (global deformation), and tensile tearing at the supports. The energy dissipated in the local deformation is determined using rigid-plastic analysis and yield line mechanisms of the deformed cross-sections. The total input energy minus the energy dissipated in local deformation is assumed to be expended in flexural deformation. Analytical solutions using the energy consumed in flexural deformation are shown to produce bounded solutions of the transverse plastic deformation of the members. Finally, a semi-empirical solution is suggested that can be used to aid in design. [Copyright &y& Elsevier] more...
- Published
- 2012
- Full Text
- View/download PDF
34. Modeling of dynamic deformation of rigid-plastic doubly connected plates with arbitrary fixed curvilinear contours on a viscoelastic foundation.
- Author
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Nemirovsky, Yu. and Romanova, T.
- Subjects
- *
VISCOELASTICITY , *DEFORMATIONS (Mechanics) , *DYNAMIC testing of materials , *RIGID bodies , *CURVILINEAR coordinates , *EQUATIONS , *MECHANICAL loads - Abstract
general solution is obtained for the problem of dynamic bending of an ideal rigid-plastic doubly connected plate with arbitrary simply supported or clamped curvilinear contours subjected to short-time high-intensity explosive dynamic loading uniformly distributed over the surface. The plate rests on a viscoelastic foundation. It is demonstrated that there are several mechanisms of plate deformation. Equations of dynamic deformation are derived for each mechanism, and implementation conditions are analyzed. Numerical examples are given. [ABSTRACT FROM AUTHOR] more...
- Published
- 2011
- Full Text
- View/download PDF
35. Numerical study on explosion-induced fractures of reinforced concrete structure by beam-particle model.
- Author
-
Liu, Jun, Zhao, ChangBing, and Yun, Bin
- Abstract
In the field of disaster prevention mitigation and protection engineering, it is important to identify the mechanical behaviors of reinforced concrete (RC) under explosive load by simulation. A three dimensional beam-particle model (BPM), which is suitable to simulate the fracture process of RC under explosive load, has been developed in the frame of discrete element method (DEM). In this model, only the elastic deformations of beams between concrete particles were considered. The matrix displacement method (MDM) was employed to describe the relationship between the deformation and forces of the beam. A fracture criterion expressed by stress was suggested to identify the state of the beam. A BPM for steel bar, which can simulate the deformation of steel bar under high loading rate, was also developed based on the Cowper-Symonds theory. A program has been coded using C++ language. Experiments of RC slab under explosive load were carried out using the program. Good agreement was achieved between the experimental and simulated results. It is indicated that the proposed theoretical model can well simulate the fracture characteristics of RC slab under explosive load such as blasting pit formation, cracks extension, spallation formation, etc. [ABSTRACT FROM AUTHOR] more...
- Published
- 2011
- Full Text
- View/download PDF
36. Dynamics of a rigid-plastic curvilinear plate of varying thickness with an arbitrary hole.
- Author
-
Nemirovskii, Yu. V. and Romanova, T. P.
- Subjects
- *
STRUCTURAL plates , *APPLIED mechanics , *BOUNDARY value problems , *NUMERICAL analysis , *MATHEMATICAL models - Abstract
perfect rigid-plastic body is used as a model to develop a general procedure for analyzing the dynamic behavior of an arbitrary curvilinear plate of variable thickness with an arbitrary internal hole. The plate is subjected to an arbitrary, uniform, short-term dynamic surface load. Two plate deformation patterns are considered. Analytic formulas for plastic zones, ultimate loads, and residual deflections are presented. Numerical examples are given [ABSTRACT FROM AUTHOR] more...
- Published
- 2010
- Full Text
- View/download PDF
37. A Study on the Control of Fragments from a Detonation Deformable Directional Warhead.
- Author
-
CHEN Fang, ZHANG Han, MA Xiao-qing, and ZHANG Hu-cheng
- Subjects
DETONATION waves ,DEFORMATION potential ,DEFORMATIONS (Mechanics) ,BLAST effect ,RADIOGRAPHY ,WARHEADS - Abstract
Based on the study on a detonation deformable directional warhead, the theoretical model about the deformation of the shell is set up, and the function is established about the initial velocity and the spray angle of the fragments. Flash X-ray photography experiment and static experiments have been made, and it was shown that the theoretical results are similar to the experimental results. [ABSTRACT FROM AUTHOR] more...
- Published
- 2009
38. Blast Resistance of 240 mm Building Wall Coated with Polyurea Elastomer.
- Author
-
Ji, Long, Wang, Ping, Cai, Youer, Shang, Wei, and Zu, Xudong
- Subjects
- *
WALLS , *ELASTOMERS , *BRICK walls , *BLASTING , *MASONRY , *COUNTERTERRORISM - Abstract
Enhancing the blast resistance of building walls is a research hotspot in the field of anti-terrorism and explosion protection. In this study, numerical simulation and experimental verification were combined to analyze the failure phenomenon of brick masonry wall and sprayed polyurea-reinforced brick wall under contact explosion and determine the failure response parameters of the wall. The failure limit, mode, and mechanism of a 240 mm wall without reinforcement and strengthened with polyurea elastomer under different strength loads were investigated. Under contact explosion, the increase in the size of the blasting pit of the 240 mm wall gradually slowed down after the dose was increased to higher than 0.5 kg. Thereafter, the energy of the explosive load was released by splashing wall fragments as well as by deflecting and movement of the wall. The results show that the 240 mm walls sprayed with polyurea elastomer had outstanding anti-explosion performance because it wraps the damaged area and fragments of masonry wall inside the polyurea layer. When the thickness of the polyurea layer increases to 8 mm, the damaged area of the masonry wall decreases by 55.6% compared with that without reinforcement. The numerical simulation results were in good agreement with the experimental results. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
39. Energy absorption of aluminium alloy circular and square tubes under an axial explosive load
- Author
-
Karagiozova, D., Nurick, G.N., and Chung Kim Yuen, S.
- Subjects
- *
ALUMINUM alloys , *TUBES , *MECHANICAL buckling , *LIGHT metals - Abstract
Abstract: The energy absorption of circular and square aluminium alloy tubes subjected to an axial explosive load, which is transmitted to a tube by a small attached mass, is discussed. Particular attention is paid to the interaction between the inertia of the attached mass and a tube when the importance of the initial compression phase is revealed. The effect of this phase on the mean load, which is characteristic of the energy absorption capacity of structural elements, is demonstrated. The influence of the material models on the prediction of the response of aluminium alloy circular and square tubes is also discussed in relation with the temperature effects caused by the high strain rates. The analysis shows that the material properties play an important role for the formation of the buckling pattern due to the finite duration of the initial compression phase when plastic stress waves at different speeds propagate along a shell. [Copyright &y& Elsevier] more...
- Published
- 2005
- Full Text
- View/download PDF
40. Modeling the effects of high strain rate loading on RC columns using Arbitrary Lagrangian Eulerian (ALE) technique
- Author
-
Abedini, Masoud, Mutalib, Azrul A., Raman, Sudharshan N., Akhlaghi, Ebrahim, Abedini, Masoud, Mutalib, Azrul A., Raman, Sudharshan N., and Akhlaghi, Ebrahim
- Abstract
In recent years, many studies have been conducted by governmental and nongovernmental organizations across the world in an attempt to better understand the effect of explosive loads on buildings in order to better design against specific threats. This study is intended to contribute to increase the knowledge about how explosions affect reinforced concrete (RC) columns. In this study, a nonlinear model is developed to study the blast response of RC columns subjected to explosive loads. Numerical modeling of RC column under explosive load is presented using advanced finite element code LS DYNA. The obtained numerical model is validated with the experimental test and the results are in substantial agreement with the experimental data. ALE method for blast analysis is presented in the current research. The effects of scaled distance on the damage profile of RC columns are investigated. The results demonstrate that the level of damage increased with describing the scaled distance. Also the results shown duration for the blast loading, and hence the impulse, varies with charge masses at the specified scaled distance. Higher magnitude charge masses produced longer blast loading durations than lower magnitude charge masses. This means that at the same scaled distance, a charge mass of higher magnitude produced a higher impulse than the lower magnitude charge mass. The findings of this research represent the scaled distance is an important parameter that should be taken into account when analyzing the behavior of RC columns under explosive effects. The data collected from this research are being used to improve the knowledge of how structures will respond to a blast event, and improve finite element models for predicting the blast performance of concrete structures., Peer Reviewed more...
- Published
- 2018
41. Modeling the effects of high strain rate loading on RC columns using Arbitrary Lagrangian Eulerian (ALE) technique
- Author
-
Ebrahim Akhlaghi, Masoud Abedini, Azrul A. Mutalib, and Sudharshan Naidu Raman
- Subjects
Engineering, Civil ,High strain rate ,Materials science ,Explosive Load ,Engineering, Multidisciplinary ,02 engineering and technology ,Matemàtiques i estadística::Anàlisi numèrica [Àrees temàtiques de la UPC] ,0203 mechanical engineering ,0202 electrical engineering, electronic engineering, information engineering ,Engineering, Geological ,Engineering, Ocean ,Engineering, Aerospace ,Anàlisi numèrica ,ALE Method ,Applied Mathematics ,Scaled Distance ,General Engineering ,LS DYNA ,Mechanics ,Arbitrary lagrangian eulerian ,Engineering, Marine ,Rc columns ,Engineering, Mechanical ,Engineering, Manufacturing ,020303 mechanical engineering & transports ,Engineering, Industrial ,020201 artificial intelligence & image processing ,Mathematical & Computational Biology ,Numerical analysis - Abstract
In recent years, many studies have been conducted by governmental and nongovernmental organizations across the world in an attempt to better understand the effect of explosive loads on buildings in order to better design against specific threats. This study is intended to contribute to increase the knowledge about how explosions affect reinforced concrete (RC) columns. In this study, a nonlinear model is developed to study the blast response of RC columns subjected to explosive loads. Numerical modeling of RC column under explosive load is presented using advanced finite element code LS DYNA. The obtained numerical model is validated with the experimental test and the results are in substantial agreement with the experimental data. ALE method for blast analysis is presented in the current research. The effects of scaled distance on the damage profile of RC columns are investigated. The results demonstrate that the level of damage increased with describing the scaled distance. Also the results shown duration for the blast loading, and hence the impulse, varies with charge masses at the specified scaled distance. Higher magnitude charge masses produced longer blast loading durations than lower magnitude charge masses. This means that at the same scaled distance, a charge mass of higher magnitude produced a higher impulse than the lower magnitude charge mass. The findings of this research represent the scaled distance is an important parameter that should be taken into account when analyzing the behavior of RC columns under explosive effects. The data collected from this research are being used to improve the knowledge of how structures will respond to a blast event, and improve finite element models for predicting the blast performance of concrete structures. more...
- Published
- 2018
- Full Text
- View/download PDF
42. The Optimal Location of the Polygonal Internal Supports to the Circular Rigid-Plastic Plates
- Author
-
Tatyana P. Romanova
- Subjects
optimal location of support ,final deflection ,lcsh:Mathematics ,rigid-plastic plate ,explosive load ,limit load ,lcsh:QA1-939 ,internal polygonal support ,circular plate - Abstract
The general solution of a problem of the limit behavior and dynamic bend is obtained for the perfect rigid-plastic circular plates, hinge supported on immobile polygonal contour, located inside the plate. The plate is subjected to short-term dynamic load of explosive type with high intensity, uniformly distributed over the surface. It is shown that there are several mechanisms of limit and dynamic deformation of plates depending on the location of the support contour. The simple analytic expressions are obtained for the limit load and maximum final deflection of plates. The optimal location of support and the number of sides of the polygonal contour are determined, at which the plate has maximum limit load. Numerical examples are given. more...
- Published
- 2014
43. Computational predictions for estimating the maximum deflection of reinforced concrete panels subjected to the blast load.
- Author
-
Shishegaran, Aydin, Khalili, Mohammad Reza, Karami, Behnam, Rabczuk, Timon, and Shishegaran, Arshia
- Subjects
- *
BLAST effect , *REINFORCED concrete , *CONCRETE panels , *SURROGATE mothers , *REGRESSION analysis , *STANDARD deviations - Abstract
• We investigate the resistance of reinforced concrete panels (RCPs) due to explosive loading using nonlinear finite element analysis and surrogate models • Increasing the thickness of RCP and compressive strength of concrete has the most positive effect on reducing the damage and maximum deflection of RCP under blast loading. • MLnER is selected as the best surrogate model to predict the maximum deflection of RCPs. We investigate the resistance of reinforced concrete panels (RCPs) due to explosive loading using nonlinear finite element analysis and surrogate models. Therefore, gene expression programming model (GEP), multiple linear regression (MLR), multiple Ln equation regression (MLnER), and their combination are used to predict the maximum deflection of RCPs. The maximum positive and negative errors, mean of absolute percentage error (MAPE), and statistical parameters such as the coefficient of determination, root mean square error (RMSE). Normalized square error (NMSE), and fractional bias are utilized to evaluate and compare the performance of the models. We also present a novel statistical table to demonstrate the distribution of percentage errors indicating that MLnER is the best model for predicting the maximum deflection of RCPs under blast loading. We also carry out a detailed parameter study. The independent variables include the weight of charge, standoff distance, panel thickness, panel dimensions, reinforcement ratio, the compressive strength of concrete and yield strength of the reinforcement. We find that the key parameters are the panel thickness and compressive strength with respect to the explosive strength of RCPs, and the explosive weight and distance from the explosive have the most impact on the RCP failure. [ABSTRACT FROM AUTHOR] more...
- Published
- 2020
- Full Text
- View/download PDF
44. Determination of Pressure in a Metal Plate at Propagation of Loading Over the Plate Surface
- Author
-
Pai, V. V., Simonov, V. A., Meyers, Marc A., editor, and Murr, Lawrence E., editor
- Published
- 1981
- Full Text
- View/download PDF
45. New technologies explosive cladding and hardenings
- Subjects
graphite coatings ,покрытие ,трехслойное сферическое днище ,плёнка ,взрывная нагрузка ,графитовое покрытие ,explosive load ,spherical bottoms ,монолитная кромка - Abstract
Определены параметры устойчивого взрывного плакирования поверхностей деталей покрытиями и пленками толщиной 200-300 nm и графитовых покрытий и пленок толщиной 10-100 nm. Апробирована технология модифицирующего воздействия взрывной нагрузки и получения монолитных кромок трехслойных сферических днищ. The parameters of sustained explosive cladding surfaces of the parts coatings and film thickness of 200-300 nm, and graphite coatings and film thickness of 10-100 nm are indentified. The technology of modifying effects of the explosive load and get solid edge sandwich spherical bottoms are tasted. more...
- Published
- 2011
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