两个相等圆孔板弯曲时的三维应力集中

根据Hellinger-Reissner原理建立了具有一个无外力圆柱表面的三维八节点杂交应力元，其假设应力场严格满足柱坐标下三维平衡方程及圆柱面上无外力边界条件；当元退化为二维时也满足协调方程。数值算例表明，这种特殊杂交应力元可高效地分析具有两个圆孔薄板和厚板的应力集中，特别是三维应力集中。

Investigation of 3-D stress concentration in a plate with two equal circular holes under bending

A 3\|D 8\|nodes hybrid stress element with a traction\|free cylindrial surface has been developed based on the Hellinger\|Reissner principle. The assumed stress field exactly satisfies the equilibrium equations as well as the traction\|free boundary condition. It also satisfies the compatibility condition when the element is degenerated into 2\|D case. Numerical results show that the special assumed stress element can be efficiently used for stress analyses around two circular holes in a thin or thick plate under bending.