半无限大体中次表面裂纹间的相互影响

Interaction Among Subsurface Cracks in an Elastic Half-Plane

针对钢轨次表面的微裂纹问题,采用含裂纹的半无限大体进行简化,研究了半无限大体中裂纹间的相互影响。利用弹性力学中半平面体在边界上受法向分布力的应力公式求出裂纹面上的应力,并采用Kachanov简化方法,得到了裂纹尖端的应力强度因子。分析了裂纹与表面的距离、裂纹尺寸和裂纹之间的距离对裂纹尖端应力强度因子的影响。结果表明:裂纹与表面的距离越大裂纹间的影响越小,裂纹尺寸越大裂纹间的影响越大,裂纹之间的距离越大裂纹间的影响越小。

It is simplified as a half-plane contains micro-cracks for the problem of micro-cracks on the subsurface of the rail. It analyzed the interaction between the micro-cracks in the half-plane. The tractions along the cracks are obtained from the stress formula of a half-plane subjected to a normal distribution force at the boundary in the elastic mechanics. Based on Kachanov＇s simplified method,the solution of a half-plane containing the micro-cracks is presented. The stress intensity factor at the crack tip is obtained and the interaction among collinear micro-cracks is analyzed. The results show that the interaction among cracks decreases with the distance among the cracks increasing,and the distance between the micro-crack and the surface increasing and the crack size decreasing.