具有表面凹坑的半无限体三维应力集中系数有限元研究

The Finite Element Study of Three-Dimensional Stress Concentration Factor of Half Infinite Solid with Surfact Notch

利用ANSYS有限元软件对半无限体表面球形和半椭球形凹坑的三维应力集中系数进行了计算 ,该方法简单易行 ,省时省力 ;并将所得数据与试验结果作了对比 ,两者吻合较为一致 ,说明利用该软件分析三维应力集中问题有效可行。研究结果表明 :应力集中系数随泊松比 μ、曲率r及凹坑与结构相对尺寸的增加而变大 ;对于椭球凹坑 ,在深度一定时 ,增加凹坑与表面相交面积 ,可以减小应力集中系数 ,削去部分的形状 ,以与凹坑相切 。

The three dimensional stress concentration factor of half infinite solid with surface spherical or half ellipsoidal notch is studied with the ANSYS software. The results given by the method of FE are in good agreement with the experimental data. The numerical results show that stress concentration factor value increases with the increase of Poisson's ratio μ and curvature r and the relative size of notch. When the depth of ellipsoidal notch is constant, stress concentration factor can be decreased by inereasing the intersection area of notch and solid surface. It is better that the cutting is tangent to the notch and the long wxis of the ellipse is along the loading direction at the same time.