玻璃态高聚物的损伤和断裂非平衡统计理论（2）玻璃态高聚物细观损伤统计本构方程

从银纹瞬时成核和以指数形式衰减两种成核模型出发，根据前文给出的微裂纹尺寸统计分布函数及其矩生成函数，基于一阶平均损伤函数的唯象定义，得到了在两种成核机理下的细观统计损伤本构方程和损伤速率的解析表达式．对于各向同性材料，考虑到泊松比随应变而变化，又给出了以应变及应变速率表示的细观损伤统计本构方程．从而把应力、应变、应变速率、温度、时间及材料参数有机地结合起来，为玻璃态高聚物各种力学性能的理论与实验的对比提供了可能．

Nonequilibrium Statistical Theory of Damage and Fracture for Glassy Polymers (2) A Mesodamage Statistical Constitutive Equation for Glassy Polymers

A statistical constitutive equation is formulated for describing the mesodamage behavior or glassy polymers. Based on the phenomenological definition of the first-order averaged damage function obtained in our previous work, the generally analytic expressions of meso-statishcal damage equation and its damage rate arc derived, which have clearly mesophysical meanings. Considering the changes of the Poisson ratio with strain, in that case the relation of the mesodamage statistical equation to the inFinitive small strain for isotropic materials is deduced specially, two different models of craze nucleahon, namely, instantaneous nucleation and decay by exponent law, are discussed. The distribution function of microcrack size, the first-order averaged damage function, damage variable and strain arc also given mathematically. It is successful in relating the mechanical properties (such as stress, strain) to the intrinsic parameter of materials and to the test conditions (such as temperature, strain rate). The correlations provide us a possibility for comparing the theory with experimental results of glassy polymers.