角单元对薄壁管耐撞性的影响

Influence of Angle Element on Crashworthiness of Thin-Walled Tubes

角单元对薄壁管的吸能特性影响显著,现有的关于耐撞性的研究只针对特定角度的角单元,不具备普遍性。文中将凹角引入薄壁管的截面形状设计中,提出一种新型的凹角管,实现了90°到180°之间任意角单元对薄壁管耐撞性影响的分析。首先,对一系列不同角度的薄壁管进行了轴向碰撞仿真;然后,利用超折叠单元理论定量推导出角单元与薄壁管轴向冲击平均力的表达式;最后,对理论预测结果和数值仿真结果进行了对比。研究结果表明:角单元角度显著地影响着凹角管的变形模式;当角单元角度为90°时,薄壁管有良好的耐撞性;薄壁管的平均力F m和总吸能量EA随着角单元角度的增加而降低,当角单元角度从100°变为170°时,F_(m)和EA分别降低了45.64%和46.84%。

Angle element has a significant effect on the energy absorption characteristics of thin-walled tubes.However,the existing researches only focus the influence of angle elements at specific angles.This paper introduced concave corners into the cross-section design of thin-walled tubes and put forward a new kind of concave tube to investigate the influence of angle element between 90°and 180°on crashworthiness.Firstly,the axial collision simulation of a series of thin-walled tubes with different angles was carried out.Secondly,the expression of the mean axial crushing force of angle element and thin-walled tube was derived quantitatively by using super-folding element theory.Finally,the theoretical prediction results were compared with the numerical simulation results.The results shows that:the angle of angle element significantly affects the deformation modes of concave tubes;the thin-walled tube has good crashworthiness when the angle element is 90°;the average force F m and total energy absorption EA of the thin-walled tube decrease with the increase of angle of angle element.When the angle of angle element increases from 100°to 170°,F_(m) and EA decrease by 45.64%and 46.84%,respectively.