薄壁方管结构在爆炸荷载作用下动力响应及破坏模式分析

摘要

Numerical simulations and experimental tests were carried out on the dynamic responses of thin-walled steel square hollow tubes subjected to explosion loading.The impact experiments of explosion loading caused by 200 g TNT charge on the steel square tubes were carried out.The deformation modes and damage modes were obtained under different conditions.The experimental results show that when the charge distance is greater than or equal to 14 cm,the structures will undergo local deformation only.When the charge distance is equal to 10 cm or 12 cm,the structures will undergo both local and global deformations.The experimental results also show that the two side walls facing explosion display long strip rupture damage.By using LS-DYNA,the deformation and damage processes of thin-walled tubes subjected to explosion loading were numerically simulated with Lagrangian-Eulerian coupling method.The deformation processes of thin-walled tubes as well as the deflection-time curves at some key points were also obtained.The dynamic responses of the square tubes affected by the width to thickness ratio were analysed.The results show that the deformation decreases with the decreasing of the width to thickness ratio.%采用数值模拟与实验相结合的方法研究了薄壁方管结构在爆炸荷载作用下的动力响应。将壁厚3 mm、截面边长为100 mm 的薄壁方管结构置于200 g TNT 产生的爆炸场中进行冲击实验，实验表明当装药距离大于等于14 cm时，结构仅呈现局部凹陷变形，当装药距离为10 cm 和12 cm 时，结构除局部凹陷变形外，还呈现出整体变形模式，同时，方管迎爆面两侧边产生长条状破裂损伤。利用动力有限元程序 LS-DYNA 及流固耦合算法对薄壁方管变形及破坏过程进行数值模拟，得到了结构关键单元处压力分布、挠度时间曲线等参数。同时分析了结构宽厚比对试件动力响应的影响，结果表明迎爆面变形量随着宽厚比的减小而减小。