垂直于界面V型缺口尖端的应力奇异性及其应用

基于双材料垂直于界面V型缺口理论,给出了单一材料和双材料裂纹问题、V型缺口问题应力强度因子的统一定义,得到了应力外推法计算双材料K_I的公式,数值算例验证了本文方法的有效性.以双材料单向拉伸和三点弯曲模型为对象,深入研究了双材料中弹性模量、泊松比、缺口深度、缺口张角对缺口尖端奇异应力场的影响,获得了一定范围内各种参数变化对缺口尖端奇异应力场的影响规律,为异体材料形成的V型缺口在应力断料中的应用提供了必要的参考依据.

Stress Singularity Near Tip of V-Shaped Notch Normal to Bimaterial Interface

Based on the theory of a V-shaped notch normal to bimaterial interface, a generalized expression of the stress intensity factor is provided for a crack in single material, a V-shaped notch in single material, a crack normal to bimaterial interface and a V-shaped notch normal to bimaterial interface, and then, a formula of stress extrapolation method for calculating the stress intensity factors of bimaterial models is obtained. The validity of stress extrapolation method is verified by the numerical examples. Taking double edge cracks in finite plate loaded by uniform tension and three-point bending specimen as objects investigated, the influences of elasticity modulus, Poisson ratio and notch depth and notch angle on singular stress fields near the tip of the V-shaped notch are analyzed in detail, the Influencing law of various parameters which varies within limits on singular stress field are acquired, consequently, these results provide necessary theoretical foundations for stress blacking of V-shaped notch by dissimilar materials.