基于分子动力学的结合材料界面破坏准则

结合材料的破坏通常都是从界面或其附近发生的,但界面破坏的机理及其评价准则尚未十分清楚.采用分子动力学模拟方法,可以对结合材料的界面破坏过程进行模拟,从而获得结合材料的界面应力和界面破坏之间的关系.界面破坏可以分为奇异应力场作用下的破坏,和界面应力集中引起的破坏两种.虽然在分子动力学模拟中采用了高度简化的界面模型,但对界面破坏过程的模拟,仍可以帮助人们获得结合材料界面破坏过程的规律性认识.分别模拟远场作用下界面上存在初始裂纹和界面附近存在初始裂纹两种情况下的界面破坏,根据分子动力学模拟结果,提出了一个结合材料界面破坏的准则.

A Bi-Material Interface Fracture Criterion Based on Molecular Dynamics

Fracture of bi-material often occurs at or near the interface,but the mechanism and criterion of interface fracture are not clear yet.A molecular dynamics simulation method was introduced to simulate the interface fracture,from which the correlations between the interfece stress and the interface fracture were acquired.Interface fracture can be caused by singular stress field and interface stress concentration.In molecular dynamics simulation,a quite simplified model was used,but the simulation for the process of interface fracture also helps to acquire some rules about bi-material interface fracture.Two cases:(a) initial crack exists at interface;(b) initial crack exists near interface were simulated.From the simulation results of the two cases subjected to remote load,a bi-material interface fracture criterion was proposed.