Shock enhancement in cellular structures under impact loading by finite element simulation

摘要

In recent years, strength enhancement of cellular structures under impact loading has been foundnby some scientists during experiments. However, the influence of the impact velocity and relativendensity of the materials on the shock enhancement has seldom been studied. In this paper, thenimpact response of aluminium foam and its dependence on relative density and impact velocitynare analysed using the finite element method. The simulation results show that at the large impactnvelocity, the elastic wave as the pioneer goes through the whole sample and makes the samplenequilibrating. When the stress exceeds the plateau stress of the material and makes it densified,nthe shock wave will be generated and lead to stress unequal at the two ends of the specimennwithin a certain period. Shock enhancement of the cellular structure becomes more significantnwith lower relative density and high impact velocity. The estimated shock front velocity increasesnwith both impact velocity and relative density.