一种新的岩石多尺度本构模型:增强虚内键模型及其应用

摘要

Based on the meso-structure, the present paper employs the augmented virtual internal bond(AVIB) to model rock, thereafter to simulate fracture propagation in rock. The AVIB is a constitutive model that was developed based on the theory of virtual internal bond(VIB). It uses the Xu-Needleman potential function to describe the micro bond, which is very suitable for modeling the cohesive properties of mineral grain interface. For the constitutive model implicitly contains the micro bond rupture mechanism, it doesn't need separate fracture criterion when simulating fracture propagation and coalescence. Moreover, by AVIB, the complex 3D fracture behaviors can trace back to the ID micro bond rupture process. These features of AVIB make it powerful in analysis of rock failure. The purpose of the paper is to provide a new theory for multiscale modeling and fracture simulation method for rock.%在细观结构基础之上,应用增强虚内键(augmented virtual internal bond,AVIB)模型对岩石进行本构建模,得出岩石宏观本构方程,从而对岩石断裂行为进行模拟.AVIB模型是在虚内键(VIB)理论基础上发展起来的一种新型多尺度本构模型.它在微观层面上将固体材料视为由随机分布的材料颗粒组成,颗粒之间的相互作用由Xu-Needleman势函数描述,基于Cauchy-Born规则,在超弹理论框架内直接由微观作用势导出宏观本构方程.由于在AVIB本构方程中已包含了微观虚内键断裂机制,因而它在模拟岩石宏观断裂过程中无需额外的断裂准则,AVIB模型可以将宏观复杂三维断裂问题溯源到微观一维虚内键断裂问题,这些特点为岩石断裂破坏分析提供了很大的方便,为岩石多尺度本构建模和断裂模拟提供一种新的理论和方法.