A Virtual Internal Bond Approach to Fracture Simulatiion

我们提出了一种新的内聚断裂理论的基础上，从经验的凝聚力法构建连续本构模型的方法。该理论旨在克服断裂力学应用的常规理论的一些局限性，所述断裂力学应用涉及断裂韧性变得敏感地依赖于器件几何形状的微米级结构中的裂纹成核和生长。与在有限元离散化阶段引入一组具有有限断裂功和有限内聚强度的离散内聚面模型（Xu和Needleman，1994; Camacho和Ortiz，1996）相比，本文提出将内聚力定律直接嵌入本构模型中。我们的初步研究（Gao和Klein，1998; Klein和Gao，1998）表明，这种方法实际上是可行的。

We propose a novel cohesive theory of fracture based on a method of constructing continuum constitutive models from an empirical cohesive force law. This theory is aimed to overcome some of the limitations of the conventional theory of fracture mechanics applications involving crack nucleation and growth in micron scale structures where fracture toughness becomes sensitively dependent on device geometry. In comparison with the cohesive surface models (Xu and Needleman, 1994; Camacho and Ortiz, 1996) in which a set of discrete cohesive surfaces having finite work of fracture and finite cohesive strength is introduced at the stage of finite element discretization, we propose to embed a cohesive force law directly into the constitutive model. Our preliminary studies (Gao and Klein, 1998; Klein and Gao, 1998) have shown that this type of approach is practically feasible.