A New Damage Model of Microvoids

With introducing the concept of the number of micro-damage in unit volume, macro damage parameter and microvoids volume are unified together, and a new kind of quadratic micro-voids damage evolution equation is acquired. The effect of inertia is considered during the expansion of voids. The expansion of surface and inertia will play a dominant role during the different stage of expansion of voids respectively. After taking the impact experiment of 921 steel as reference and comparing the curves of free surface velocity, the model is proved to be correct since their results are matched well.