摘要
本文从现象学观点出发,在定义损伤材料有效应力及有效塑性应变的基础上,根据不可逆热力学基本原理,得到了等效虚拟弹塑性热力学状态的有效广义摩擦系数。从Gibbs自由能体系出发,推导出了弹塑性损伤材料的三维本构方程。在这一过程中,损伤对塑性内变量的贡献,通过其二阶张量定义,并由等效的Burger位错矢量的井矢表征。从而考虑了弹塑性与损伤的交互作用影响。此外,本文从热力学耗散机制出发,通过引进一个有效的广义摩擦力函数,获得了以耗散势表示的损伤演化方程,并且容易得到显式。最后,本文对给出的损伤本构方程及损伤演化方程进行了讨论,得到一系列有益的结果。
From the point of view of phenomenology. defining the effective stress and the ef-fective plastic strain of the elastoplastic damage materials, the effective generalized fric-tion coefficient of equivalent virtual elastoplastic thermodynamic state is obtained basedon the theory of irreversible thermodynamics, and then the three-dimensionalconstitutive equation for the elastoplastic damage materials is deduced, which consid-cred the effect of damage contribution on the effective plastic strain, which is expressedby a sct of second-order tensor involving the equivalent Burger's dislocation vector ofdamage, considered the interactive effect of elastoplastic and damage. By means of thethermodynamic dissipation mechanism, through introducing the effective generalizedfriction force, the evolution equation of damage under the different plastic strain is alsodeduced. Finally both the constitutive equation and the evolution equation of damageare discussed and a series of useful results are given.
关键词
弹塑性
损伤材料
应力
本构方程
effective stress
effective plastic strain
constitutive equations / elastoplastic damage
evolution equations
