基材的应变强化效应对蜂窝缓冲性能的影响

Influence of cell wall material on the cushioning properties of honeycombs caused by its strain hardening effect

采用数值模拟的方法研究了基材的应变强化效应对正六边形蜂窝在共面冲击载荷下的变形模式和缓冲性能的影响。为了定量表示基材的应变强化效应,定义了强化参数珚E;保持蜂窝结构参数一定,建立不同珚E值的蜂窝样品在不同加载速度下的有限元模型,并进行大量的模拟计算,获得相应的变形模式和响应曲线.结果显示,随着冲击速度的增加,蜂窝芯材依次出现了"X"字形、"V"字形、"一"字形三种变形模式,基体材料的应变强化效应使变形趋于均匀化;与弹性理想塑性材料相比,基体材料的应变强化效应能够引起蜂窝动态峰应力和能量吸收的增长,但是冲击速度的增加会抑制这种影响.

The influence of the cell wall material strain hardening effect on the deformation mode and cushioning properties of regular hexagonal honeycomb under in-plane impact loadings was investigated by numerical simulation.In order to quantify the strain hardening effect of the cell wall material,a hardening parameter,is defined.By keeping the honeycombs′configuration parameters were fixed and setting different loading velocities,the finite element models of honeycomb specimens with different values of were established.Then a great deal of simulation calculations were performed and the related deformation mode and responses curves were obtained.These results showed that there are three kinds of deformation modes,such as X-shape,V-shape and I-shape with the increase of the impact velocity,and the deformation tends to be homogenized caused by the strain hardening effect of the cell wall material.The stress-strain curve,dynamic peak stress curve and energy absorption curve of the honeycomb core were also obtained by post-processing.Based on these mechanical response curves,we can conclude that honeycomb plateau stress and energy absorption would increase because of the strain hardening effect of the cell wall material.But this influence would be restrained with the increase of the impact velocity.