延性材料动态破碎机理及初始损伤效应

运用Ｐｅｒｚｙｎａ的粘塑性过应力本构模型，分析了延性材料动态破碎的细观机理，给出了破碎尺寸与材料孔隙度的关系。此外。研究了初始损伤度对材料动态碎的是影响。结果表明，在初始损伤较小时，破碎尺寸随机隙度增加而减小；而当初始损伤较大时，破碎尺寸随孔隙度增加而增大。这反映出材料的破碎是一个时间盯关过程或累积过程。

Dynamic Fragmentation Mechanism of Ductile Materials and the Effects of Initial Damage

A viscoplastic constitutive equation proposed by Perzyna was employed toinvestigate the mesomechanism of dynamic fragmentation of ductile materials. The fragment she versus material porosity was provided and the influence of initial damage ondynamic fragmentation was studied. The resultS showed that the fragment size had anincreasing trend with the groWth of material porosity as the initial damage was over acertain value, otherwise, the fragment size decreased with the growth of materialporosity. These verified that the dynamic fragmentation of ductile materials was atime--duration --dependent process or namely accumulative process.