高应变率下延性多孔介质中孔洞的动态演化

本文提出了一个新的材料延性动态损伤模型，模型中不但包括了率效应，同时还考虑了惯性效应，孔洞表面能变化和材料硬化对孔洞演化的影响。此外，在模型中同时考虑了体应力和偏应力对孔洞演化的作用，从孔洞演化方程地接到了孔洞增长和压缩应力临界表达式，Ｃａｒｒｏｌｌ和Ｈｏｌｔ结果作为该表达式的一个特例而得出，模型的数值分析得出以下结论：①延性孔洞的动太增长对率效应十分敏感，应变率越高，孔洞增长越快；②惯性效应在主

EVOLUTION OF VOIDS IN DUCTILE POROUS MATERIALS AT HIGH STRAIN RATE

In the present work, a dynamic damage model for ductile materials under dynamic general stresses loading is presented. The evolution equation of ductile voids has the closed form, in which work-hardening, the change of surface energy of voids, rate-dependent, inertial effects are taken into account. The expressions of critical stresses for the growth and compaction of voids are directly obtained from the evolution equations of voids. From the expressions, the result obtained by Carroll and Holt16], as a special example, is given. Numerical analysis shows that the growth of voids is sensitive to the strain rates. The growth of voids increases rapidly with an increase of strain rate. It also shows that the influence of the inertial to the void growth is significant under high loading rates. It appears to resist the growth of voids. In addition, a dynamic collapse model of ductile voids is also proposed, which can be applied to study the problems of compaction of powder and other materials.