A Virtual Internal Bond Approach to Fracture Simulatiion

本文提出了一种基于经验黏结力定律构造连续本构模型的断裂黏结力理论。该理论旨在克服传统断裂力学理论在微米尺度结构中裂纹成核和扩展的一些局限性，在微米尺度结构中，断裂韧性敏感地依赖于器件的几何形状。与黏结面模型（Xu and Needleman, 1994; Camacho and Ortiz, 1996）在有限元离散化阶段引入一组具有有限断裂功和有限黏结强度的离散黏结面相比，我们建议将黏结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.