关键词: 模型, 孔洞闭合, 椭球形孔洞, 孔洞形状改变因子, 本构方程

Abstract: A theoretical analysis on the closing proems of internal voids in materials is carried out by using Gursonˊs model of damage micromechanics and a better agreement between theory and experiment is obtained。Howevei, it is also found that stress of strain tend to have singularities when voids are closed entirely, so a new microscopic dmiage model is developed and Gursor^s equation is modified by introducing the void shape change factor. According to the constitutive relation for matermls containing voids established in the new model, the condition of the entire closing of voids is given.

Key words: model, voids closing, ellipsoidal void, void shape change factor , constitutive equation