Abstract

In this paper, the crashworthiness characteristics of tapered structures with the uniform cells in cross-section subjected to oblique impacts are theoretically and numerically investigated. Benefiting from tapered structure simplifications into the corner, crisscross and T-shape parts in non-tapered structures, an engineering formula is proposed to estimate the mean crush load during structure deformations. In order to represent the behavior of the structures subjected to oblique impacts with regard to energy absorption, an oblique impact coefficient extracted from a comprehensive parametric study on the responses of the structures is considered in the formulation. In order to conduct the parametric study, a finite element model for the crumpling processes of different tapered and non-tapered structures with the uniform cells in the cross-section under axial and oblique impacts is prepared. The contributions of cell-number in the cross-section, taper angle, wall thickness, aspect ratio and impact angel on the peak crush load, mean crush load, specific energy absorption, crush force efficiency, transition thickness and transition impact angle in the crushing processes of the tapered structures with uniform cells in cross-section subjected to oblique impacts are presented and discussed. In particular case, the predicted structural energy absorption by the numerical model is compared with those experimental results that are available in the literature, indicating a good agreement.

摘要

从理论上和数值上研究了截面为均匀单元的锥形结构在碰撞作用下的耐撞性。受益于非锥形结构中角部，十字形和T形零件的锥形结构简化，提出了一种工程公式来估计结构变形期间的平均压溃载荷。为了表示在能量吸收方面受到倾斜冲击的结构的行为，在配方中考虑了从对结构响应的综合参数研究中提取的倾斜冲击系数。为了进行参数研究，制备了一个有限元模型，用于在轴向和斜向冲击作用下，在横截面上具有均匀单元的不同渐缩和非渐缩结构的皱缩过程。横截面中的孔数，锥角，壁厚，长宽比和冲击角度对峰值破碎载荷，平均破碎载荷，比能量吸收，破碎力效率，过渡厚度和过渡冲击角的影响提出并讨论了横截面均匀的锥形结构受到斜向冲击的过程。在特定情况下，将数值模型预测的结构能量吸收与文献中提供的实验结果进行比较，表明吻合良好。横截面中的孔数，锥角，壁厚，长宽比和冲击角度对峰值破碎载荷，平均破碎载荷，比能量吸收，破碎力效率，过渡厚度和过渡冲击角的影响提出并讨论了横截面均匀的锥形结构受到斜向冲击的过程。在特定情况下，将数值模型预测的结构能量吸收与文献中提供的实验结果进行比较，表明吻合良好。横截面中的孔数，锥角，壁厚，长宽比和冲击角对峰值破碎载荷，平均破碎载荷，比能量吸收，破碎力效率，过渡厚度和过渡冲击角的影响提出并讨论了横截面均匀的锥形结构受到斜向冲击的过程。在特定情况下，将数值模型预测的结构能量吸收与文献中提供的实验结果进行比较，表明吻合良好。提出并讨论了截面均匀的锥形结构在斜冲击作用下的破碎过程中的过渡厚度和过渡冲击角。在特定情况下，将数值模型预测的结构能量吸收与文献中提供的实验结果进行比较，表明吻合良好。提出并讨论了截面均匀的锥形结构在斜冲击作用下的破碎过程中的过渡厚度和过渡冲击角。在特定情况下，将数值模型预测的结构能量吸收与文献中提供的那些实验结果进行比较，表明吻合良好。