岩石类介质的非线性动力损伤有限元模型

Non-linear Dynamic Damage Finite Elements Model for Rock Like Materials

运用连续损伤力学的概念把损伤变量引入岩石类介质的非线性本构模型,分别建立了脆性动力损伤模型和弹粘塑性动力损伤模型。模型中将损伤、渗流及孔隙率演化相互耦合的有效应力概念引入Mohr-Coulomb破坏准则,对传统的莫尔-库仑破坏准则进行修改,给出莫尔-库仑损伤破坏准则。分别对上述两种损伤模型编制了相应的有限元程序。应用上述的理论模型对建于岩石基础上的混凝土重力坝在地震荷载作用下各向同性损伤—破坏的问题分别进行了两种不同动力损伤模型的非线性数值分析。

In this paper, the damage variable has been introduced into the non-linear constitutive model of rock like medium based on the theory of continuum damage mechanics to carry out tow different dynamic damage models for the brittle cracked materials and the elasto-visco-plastic damaged medium. The explicit time integration scheme of dynamic governing equations has been taken into account of the numerical discretization in time domaino In the developed models, the concept of net effective stresses, which involve the affects of damage, pore pressure and porosity evolution in cracked rock mass has been employed into the modified Mohr-Coulomb failure criterion in order to develop a new damage failure criterion. The finite element modeling deal with these tow developed damage mechanics models has been applied for numerical simulation of dynamic damage process in geotechnical structures. Tile numerical analysis of isotropy damage-failure for a concrete dam and the rock foundation subject to earth quake loading has been presented as an example of the application of the tow developed theoretical models.