Crushing Analysis of Tapered Ellipse Tubes Under Oblique Impact Loading

Author(s):  
Qiang Gao ◽  
Liangmo Wang ◽  
Yuanlong Wang ◽  
Fuxiang Guo ◽  
Zunzhi Zhang

In this paper, a class of axisymmetric thin-walled tubes with two types of geometries (straight and tapered) and four kinds of cross-sections (square, rectangle, circle, ellipse) are considered as energy absorbing components under oblique impact loading. The crash behavior of these tubes are first investigated by nonlinear finite element analysis through LS-DYNA. It is found that the tapered tubes has the better crashworthiness performance than the straight ones under oblique impact regarding both specific energy absorption (SEA) and peak crushing force (PCF). Among the tapered tubes, the tapered ellipse tube (TET) has the best crashworthiness performance. Then by calculating the overall SEA considering load angle uncertainty effect, it is found that the weighting factors for different load angles are critical for evaluating the crashworthiness performance of the tubes.

2019 ◽  
Vol 11 (1) ◽  
pp. 41-68 ◽  
Author(s):  
Chukwuemeke William Isaac

The dynamic oblique crushing of circular thin-walled tubes with the presence of non-propagating crack was investigated numerically. The material considered was strain rate sensitive with crack located at the distal end of the tube. Major crashworthiness parameters were obtained and the analysis of the structural response for idealized and finite element crushed thin-walled tubes was also carried out. The study shows that crack initiation on energy absorbing tubes increase their crushing force efficiency under oblique impact, decrease their crushing force efficiency under axial impact and reduce their crashworthiness performance such as the energy absorption capacity and specific energy absorption under axial and oblique impact. Results of the crashworthiness parameters, deformation modes, damage morphology, stress–strain relations, absorption energy characteristics and crushing force-displacement history were obtained. Furthermore, the numerical study reveals both the desirable and undesirable consequence of crack on the overall crashworthiness performance of energy absorbing circular thin-walled tubes.


2017 ◽  
Vol 14 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Mohd. Reyaz-Ur-Rahim ◽  
P. K. Bharti ◽  
Afaque Umer

Abstract With the help of finite element analysis, this research paper deals with the energy absorption and collapse behavior with different corrugated section geometries of hollow tubes made of aluminum alloy 6060-T4. Literature available experimental data were used to validate the numerical models of the structures investigated. Based on the results available for symmetric crushing of circular tubes, models were developed to investigate corrugated thin-walled structures behavior. To study the collapse mechanism and energy absorbing ability in axial compression, the simulation was carried in ABAQUS /EXPLICIT code. In the simulation part, specimens were prepared and axially crushed to one-fourth length of the tube and the energy diagram of crushing force versus axial displacement is shown. The effect of various parameters such as pitch, mean diameter, corrugation, amplitude, the thickness is demonstrated with the help of diagrams. The overall result shows that the corrugated section geometry could be a good alternative to the conventional tubes.


2014 ◽  
Vol 663 ◽  
pp. 93-97 ◽  
Author(s):  
F. Djamaluddin ◽  
Shahrum Abdullah ◽  
A.K. Arrifin ◽  
Z.M. Nopiah

This paper presents the multi-objective optimization of aluminum foam double circular tube under oblique load for various load angle and geometry parameters. Thin-walled metallic tubes are used in vehicle structures to absorb impact energy, such as in bumper beams. In this research, aluminum alloy AA6063 T6 foam filled tube which both end were clamped, at bottom as boundary condition and at the top of tube applied quasi-static force of load angle of 0o to 30o with respect to longitudinal direction of tubes. The finite element analysis using ABAQUS code was validated according to the relevant experimental data, and the deformation modes of the tubes were studied. Multi-objective optimization design of crush parameters such as minimum peak crushing force and maximum specific energy absorption were performed using particle swarm optimization algorithm. Different optimal designs for different angles of loading and geometries of double circular tubes was identified.


2018 ◽  
Vol 12 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Giacomo Canale ◽  
Felice Rubino ◽  
Paul M. Weaver ◽  
Roberto Citarella ◽  
Angelo Maligno

Background:Beam models have been proven effective in the preliminary analysis and design of aerospace structures. Accurate cross sectional stiffness constants are however needed, especially when dealing with bending, torsion and bend-twist coupling deformations. Several models have been proposed in the literature, even recently, but a lack of precision may be found when dealing with a high level of anisotropy and different lay-ups.Objective:A simplified analytical model is proposed to evaluate bending and torsional stiffness of a prismatic, anisotropic, thin-walled box. The proposed model is an extension of the model proposed by Lemanski and Weaver for the evaluation of the bend-twist coupling constant.Methods:Bending and torsional stiffness are derived analytically by using physical reasoning and by applying bending and torsional stiffness mathematic definition. Unitary deformations have been applied when evaluation forces and moments arising on the cross section.Results:Good accuracy has been obtained for structures with different geometries and lay-ups. The model has been validated with respect to finite element analysis. Numerical results are commented upon and compared with other models presented in literature.Conclusion:For cross sections with a high level of anisotropy, the accuracy of the proposed formulation is within 2% for bending stiffness and 6% for torsional stiffness. The percentage of error is further reduced for more realistic geometries and lay-ups.The proposed formulation gives accurate results for different dimensions and length rations of horizontal and vertical walls.


2013 ◽  
Vol 438-439 ◽  
pp. 690-695
Author(s):  
Xiao Yu ◽  
Na Wu ◽  
Zhao Yang ◽  
Kai Xu

t is focused on a super high-rise building structure, of which the concrete compressive strength is reduced in joint core. The whole structure is calculated with program SATWE. Based on this calculation, integral stress analysis by MIDAS when concrete strength is reduced in joint core area and nonlinear finite element analysis by ANSYS on the joints of the worst cross-sections in the whole structure are developed. Thus the adverse effect of reduced concrete strength in joint core area on super high-rise structures is found out.


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