脆性材料动态断裂的介观格子模型

Mesoscale Lattice Model for Dynamic Fracture of Brittle Materials

岩石、陶瓷、玻璃、固体炸药等脆性材料在爆炸与冲击施加的强动载荷作用下易发生迅速的裂纹扩展和灾难性的断裂破碎,造成材料、器件、装置的功能失效和事故危害。理解脆性断裂过程中介观裂纹网络演化与宏观动态响应的关联是提升脆性材料可靠性和安全性的关键,但同时也是计算建模与数值模拟研究面临的难点。为了解决爆炸与冲击加载下脆性材料中裂纹网络随机萌生、裂纹面挤压摩擦、大量裂纹交错扩展等复杂过程带来的算法困难,一种无网格/粒子方法“格子模型”得到了持续的关注和长足的发展。本文综述了格子模型的原理和方法,介绍了运用格子模型开展脆性断裂研究的代表性成果,分析了格子模型存在的不足与改进的方向。

Rapid crack propagation and catastrophic fragmentation frequently occur in brittle materials, such as rocks, ceramics, glass and solid explosives, under intense dynamic loading imposed by the explosion and impact. Understanding the correlation between the evolution of mesoscopic crack network and the macroscopic dynamic response plays a key role to improve the reliability and the safety of brittle materials, while it still poses a great challenge to such modeling and simulation. In order to overcome the algorithm difficulties caused by complex processes, such as the random initiation of crack network, the extrusion and friction of crack surfaces, and the staggered propagation of a large number of cracks in brittle materials subjected to explosion and impact loading, the lattice model, one of meshfree methods, has received sustained attention and considerable development. In this paper, we introduce the theory and implement of the lattice model and its representative results on brittle fracture research. Its shortcomings and the direction of improvement have also been discussed.