Abstract

This study is aimed to compare and optimise the crashing performances of an axisymmetric rectangular tube (ART) and a uniform thickness tube (UTT) under offset loading. Both ART and UTT are strengthened with diaphragms. Numerical simulations for the initial UTT with diaphragms under offset loading were firstly performed based on the experimentally validated finite element model (FEM), which illustrated that deformation process varied from stable mode to bending-sliding mode with an increase offset distance of 0–60 mm. Then, design of experiment (DOE) method was employed to determine the design domains of UTT and ART under various offset distances. Based on the results of DOE, three deformation regions were identified and parametric studies showed that the thicknesses of tubes and diaphragms had significant effects on their crashing performances. Subsequently, the irregular design domains derived from the impact condition with offset distance of 45 mm were selected to search the optimal thickness configurations of both UTT and ART. Finally, the multi-objective optimisation (MOD) was conducted by using non-dominated sorting genetic algorithm (NAGA-II) to minimise the initial peak crushing force (IPCF_d) and maximise the specific energy absorption (SEA_d) under multiple offset loadings. The obtained Pareto fronts showed that ART generally achieved higher IPCF_d and SEA_d; however, ART outperformed UTT for both IPCF_d and SEA_d in certain design domains. The outcomes provide insights into the design and selection of thin-walled structures for engineering applications.

中文翻译：

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偏置载荷下轴对称且厚度均匀的矩形管的耐撞性优化

摘要

这项研究旨在比较和优化轴对称矩形管（ART）和均匀厚度管（UTT）在偏置载荷下的碰撞性能。ART和UTT都通过隔膜加强。首先根据经过实验验证的有限元模型（FEM）对带有膜片的初始UTT进行了数值模拟，结果表明，变形过程从稳定模式变为弯曲滑动模式，偏移距离增加了0-60 mm 。然后，采用实验设计（DOE）方法确定了不同偏移距离下UTT和ART的设计域。根据DOE的结果，确定了三个变形区域，并进行了参数研究，结果表明，管子和隔板的厚度对其防撞性能有重大影响。随后，从具有45 mm偏移距离的冲击条件中选择不规则设计域，以搜索UTT和ART的最佳厚度配置。最后，通过使用非支配排序遗传算法（NAGA-II）进行多目标优化（MOD），以最小化初始峰值压碎力（IPCF）_d）并在多个偏置载荷下最大化比能量吸收（SEA _d）。获得的Pareto前沿表明，ART通常达到较高的IPCF _d和SEA _d ; 但是，在某些设计领域，ART在IPCF _d和SEA _d方面均优于UTT 。结果为工程应用中的薄壁结构的设计和选择提供了见识。