矩形凸肩板拉伸和弯曲时三维应力集中

根据Hellinger-Reissner原理建立了具有一个无外力直表面的三维杂交应力元,将它和具有一个无外力圆柱面的三维杂交应力元联合,可以在相当粗的网格下有效地分析矩形凸肩厚(薄)板的三维(及二维)应力集中.

Three-dimensional stress concentration in shoulder fillets under tension and bending

Two kinds of 12-node solid finite elements were developed based on Helinger-Reissner principle by the use of assumed stress approach, the one of elements contains a traction-free planar surface, and the other contains a traction-free cylindrical surface.The assumed stresses of the elements satisfy the equilibrium equations as well as the traction-free condition over the boundary. In the limiting case of two-dimensional problem,the assumed stresses also satisfy the compatibility equations.The two-dimensional and three-dimensional stress concentration of thin and thick shoulder fillets under tension and bending are analysed by using the present special hybrid stress elements.The results show that these present special solid elements are far superior in predicting the distributions of the circumferential stresses and the stress concentration factors for the shoulder fillets.