热动力学理论在粘弹性断裂力学中的应用

THE APPLICATION OF THERMODYNAMIC THEORY IN VISCOELASTIC FRACTURE

本文基于热动力学定理推导了线性粘弹性材料的本构方程，并根据已有文献的思想列出了线性粘弹性材料的热力学平衡方程，由此推得二种全局能量释放率的表达式，同时根据虚功原理进一步推得裂尖局部能量释放率，也就说明了全局能量释放率和被广泛应用的局部能量释放率之间的等价性．本文最后给出了在正交各向异性和各向同性粘弹性介质中裂尖能量释放率的具体表达式。

Based on the thermodynamic theory, the linear viscoelastic constitutive equation is derived and the thermodynamic equilibrium equation for viscoelastic media by the method suggested by Christensen is also set out.Moreover thermodynamic equilibrium for fracture problem is presented and applied to deduce two expressions of global energy release rate. With the aid of the virtual work principle, we also obtained the local energy release rare and demostrated that the global and local energy release rate are synonymous, and the energy release being rare for the orthotropic and isotropic viscoelastic media is finally given.