Effect of Geometry on Energy Absorption of Reduction Tubes Using a Die - A Numerical Study

2013 ◽  
Vol 479-480 ◽  
pp. 599-603
Author(s):  
He Mao ◽  
Chang Jie Luo ◽  
Kai He ◽  
Ru Xu Du

The present paper deals with the numerical study of energy absorption of reduction tubes using a die subject to axial impact load. Non-linear finite element software LS-DYNA is employed to analyze the deformation pattern and energy absorption characteristics. The tubes, with the bottom ends constrained axially, deformed in necking modes by the axially moving dies. The geometries of the tubes and the dies were varied to find out the influence of the geometry parameters. The strain rate effect of the material is considered and the Cowper-Symonds equation is applied in the plastic dynamic analysis.

2013 ◽  
Vol 712-715 ◽  
pp. 1519-1526 ◽  
Author(s):  
He Mao ◽  
Kai He ◽  
Chang Jie Luo ◽  
Ru Xu Du

Reduction tube using a die is a kind of deformation tubes which are used on railway train as energy absorbers. In this paper, axial compression behavior and energy absorption characteristics of reduction tubes using a die under impact load are investigated. No-linear finite element software LS-DYNA is used to conduct the numerical study. Results for the expansion tube using a die (another kind of deformation tube) and the reduction tube using a die are compared. Assuming two different structures with the same material and sectional area, an analysis shows that the energy absorption of reduction tube is better than the expansion tube. Hence, the reduction tubes using a die are investigated using a series of numerical analysis. The relationship between displacement and load, average load are obtained. The influences of impact mass and impact velocity are discussed.


Author(s):  
Mehmet Ali Güler ◽  
Muhammed Emin Cerit ◽  
Sinem Kocaoglan Mert ◽  
Erdem Acar

In this study, the energy absorption capacity of a front body of a bus during a frontal crash was investigated. The strength of the bus structure was examined by considering the ECE-R29 European regulation requirements. The nonlinear explicit finite element code LS-DYNA was used for the crash analyses. First, the baseline bus structures without any improvements were analyzed and the weak parts of the front end structure of the bus body were examined. Experimental tests are conducted to validate the finite element model. In the second stage, the bus structure was redesigned in order to strengthen the frontal body. Finally, the redesigned bus structure was compared with the baseline model to meet the requirements for ECE-R29. In addition to the redesign performed on the body, energy absorption capacity was increased by additional energy absorbers employed in the front of bus structure. This study experimentally and numerically investigated the energy absorption characteristics of a steering wheel armature in contact with a deformable mannequin during a crash. Variations in the location of impact on the armature, armature orientation, and mannequin were investigated to determine the effects of the energy absorption characteristics of the two contacting entities.


2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987774
Author(s):  
Senqing Jia ◽  
Fusheng Wang ◽  
Lingjun Yu ◽  
Zheng Wei ◽  
Bin Xu

By applying finite element software ANSYS/LS-DYNA, finite element models of front bulkhead and main cabin are established, which aims to assess the dynamic response of fuselage structures impacted by tire fragment under bursting mode. Besides, dynamic characteristics of the two fuselage structures impacted by tire fragment are simulated and critical damage velocities of each working condition are obtained. The results show that composite front bulkhead cannot bear the impact load of front tire fragment at the velocity of 100 m/s, but aluminum alloy front bulkhead can. Main cabin with two properties both can bear the impact loads of front and main tire fragments. When impacted by front tire fragment, critical damage velocity of front bulkhead is approximately half of that of main cabin, while critical damage velocity of aluminum alloy fuselage is larger than that of composite fuselage. However, when impacted by main tire fragment, critical damage velocity of aluminum alloy main cabin is less than that of composite main cabin. Furthermore, maximum contact pressure of composite fuselage is 3–3.3 times than that of aluminum alloy fuselage. The difference in concave deformation is not significant when impacted by front tire fragment, but the difference is great when impacted by main tire fragment.


2020 ◽  
Vol 23 (15) ◽  
pp. 3307-3322 ◽  
Author(s):  
H Monsef Ahmadi ◽  
MR Sheidaii ◽  
H Boudaghi ◽  
G De Matteis

Steel plate shear wall is one of the most effective dissipation systems which are commonly used in buildings. In order to improve the hysteretic behavior of shear panels, large perforation patterns may be applied, transforming the shear plate into a sort of grid systems, where plastic deformations are concentrated on specific internal link elements. This study investigates the behavior of grid systems loaded in shear where the internal links are created by cutting out internal parts, leaving rectangular tube–shaped link elements. The influence of internal link geometry on the cyclic performance of the systems is investigated experimentally. To this purpose, two specimens that varied in the width of links were fabricated and tested. The results indicate that any increase in the width of links leads to the growth of the ultimate strength, stiffness, and energy absorption capacity. Likewise, the stress distribution and fracture tendency of the tested specimens have been simulated by the finite element software (ABAQUS) and validated according to the experimental results. Based on finite element results, a suitable analytical formulation for the prediction of the shear strength at several shear deformation demands, considering the effect of thickness of the link, has been provided. Moreover, to improve the fracture tendency of the specimens, butterfly-shaped links, which varied in the middle length, were applied. The obtained results, which have been interpreted by considering the equivalent plastic strain value, prove that the shear panel behavior improves significantly when butterfly-shaped links are considered.


2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Xiongxi Wu ◽  
Qifeng Gao ◽  
Zesong Li

Based on the computer simulation technique, this paper used the professional gear design software MASTA and finite element software ANSYS combined with the method of gear micro-modification to redesign the gear profile and eventually realized the optimization design of gear micro-modification. Then the gear transmission model of one-level reducer was established to simulate and analyze the contact equivalent stress, transmission error, and meshing impact before and after gear modification. By comparing the simulations results it is found that gear micro-modification can lower meshing impact load, reduce the vibration strength, make gear transmission steady, and improve the gear bearing capacity. By comparing the transmission error curves and meshing impact load curves before and after gear micro-modification, this helps to understand the effects of gear micro-modification on the gear transmission and provides basis references for the future redesign of the marine gears with high strength and long service life.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lian Song ◽  
Hao Hu ◽  
Jian He ◽  
Xu Chen ◽  
Xi Tu

The progressive collapse of a concrete-filled steel tubular (CFST) frame structure is studied subjected to impact loading of vehicle by the finite-element software ABAQUS, in the direct simulation method (DS) and alternate path method (AP), respectively. Firstly, a total of 14 reference specimens including 8 hollow steel tubes and 6 CFST specimens were numerically simulated under transverse impact loading for verification of finite-element models, which were compared with the existing test results, confirming the overall similarity between them. Secondly, a finite-element analysis (FEA) model is established to predict the impact behaviour of a five-storey and three-span composite frame which was composed of CFST columns and steel beams under impact vehicle loading. The failure mode, internal force-time curve, displacement-time curve, and mechanical performance of the CFST frame were obtained through analyzing. Finally, it is concluded that the result by the DS method is closer to the actual condition and the collapse process of the structure under impact load can be relatively accurately described; however, the AP method is not.


2021 ◽  
Vol 347 ◽  
pp. 00038
Author(s):  
Mujtaba M. Shuaib ◽  
Steeve Chung Kim Yuen ◽  
Gerald N. Nurick

This paper reports on the results of a numerical study to simulate the response of carbon fibre reinforced polymer (CFRP) retrofitted steel plates to applied blast loads using finite element software, LS-DYNA. The results of the simulation were validated against plate response and magnitude of deformation obtained from previous experiments. The uniform blast load was generated in the experiment by detonating a cylindrical charge down the end of a square tube. The finite element code LS-DYNA was used to simulate the structural response of the respective blast structures. For the numerical model, the blast load was simulated using the mapping feature available in LS-DYNA for the multi-material arbitrary Lagrangian-Eulerian (MM-ALE) elements which significantly reduced the size of the air domain in the model. The simulations showed a satisfactory correlation with the experiments for the blast results and post-failure deformations that occurred in CFRP retrofitted steel plates.


Author(s):  
Pengfei Ma ◽  
Shuchen Li ◽  
Huiying Zhou ◽  
Shisen Zhao ◽  
Pengcheng Wang ◽  
...  

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