利用边界单元法求平面问题应力强度因子K_I的应力-位移杂交法

本文提出用裂尖附近2点或3点的应力和位移计算应力强度因子K_I的杂交方法.这种方法充分利用了边界单元法的计算结果,考虑了裂尖应力场和位移场渐近展开式的高阶项,使用远离裂尖的点算出的K_I也有较好的精度,拟合线十分平坦.用算例的结果将杂交法与一般的位移法和应力法进行了比较,同时,对常量单元和线性单元也进行了比较.

A Hybrid Method of Stress and Displacement by BEM for Calculating Stress Intensity Factors K_I of plane Problems

In this paper, a hybrid method for calculating stress intensity factors K_(?) of plane problems is proposed. This method makes an efficient use of the output from boundary element method, i. e. , the stresses and displacement of two or three points near the crack tip, and considers higher order terms in the asymptotic expansions of stress and displacement fields near the crack tip. The computed K_(?) values have good accuracy even with calculating points far away from the crack tip, the fitted line is very even. Comparisons are made between results from the hybrid method and those from common displacement method or stress method. Meanwhile, comparison of results using constant elements and linear elements is also made.