多孔材料冲击波效应的数值模拟

采用有限元方法模拟了开孔泡沫铝在冲击载荷下的响应,研究了冲击响应与相对密度和冲击速度的关系。研究结果表明:开孔泡沫铝受到较大速度冲击时,先驱产生的弹性波使试样达到准平衡状态。当试样受冲击端的应力超过平台区应力达到密实化区的应力时,冲击波产生。冲击波的形成将使试样两端的应力在一定的时间内不平衡,产生冲击波效应。具有相同的相对密度时,冲击速度越大,冲击波效应越明显,冲击波速度也越大;在相同的冲击速度下,相对密度越大冲击波效应越不明显。

Finite Element Simulation of Shock Enhancement in Cellular Structures Under Impact Loading

In order to study the shock reinforcing effect of the cellular structures,the finite element method was used to simulate the dynamic response of aluminum foam under impact loading.The relationship of impact response and relative density and impact velocity was studied.The simulation results show that under large impact velocity,the elastic wave as the pioneer goes through the whole sample and makes the sample equilibrating.When the stress exceeds the plateau stress of the material and goes to the dense area of the material,the shock wave generates and leads to stress unequal at the two ends of the specimen within a certain period.Shock enhancement of the cellular structure becomes more significant at high impact velocity with the same relative density.The shock enhancement is not obvious at higher relative density with the same shock velocity.