损伤力学中的能量等效假设及其实验验证

大多数损伤模型在构造受损材料本构方程时所采用的应变或应力等效假设在一般情况下并不能满足热力学理论的基本规则.本文提出的能量等效假设,在弹性、塑性和蠕变损伤等普遍情形均证明了其有效性.同时,能量等效假设配合以应变能密度准则,可以很好地描述穿孔铜薄板试件的破断行为.

Hypothesis of Energy Equivalence in Continuum Damage Mechanics and its Experimental Verification

The so-called basic postulate of strain or stress equivalence as used by most damage models is found to be rather restrictive in the consturction of constitutive equations for materials sufferring from progressive deterioration,especially when anisotropic damage is involved. A new hypothesis of energy equivalence is presented in this paper which extends the more familiar hypothesis of elastic strain energy equivalence to phenomena other than elasticity. Feasibility of the hypothesis is demonstrated through several practical examples including plasticity and creep which are coupled with anisotropic damage. This is further supported by the close agreement between the predicted and measured rupture stresses of thin plate specimens with various prescribed perforation patterns.