含随机裂纹结构的弹塑性断裂分析

Elasto-plastic fracture analysis for structures containing stochastic crack

压力容器的失效大多为弹塑性断裂失效 ,CEGBR6、PD64 93、SAPV95等规范都采用J积分参量进行断裂评价。开展了裂纹尺寸为随机变量时的弹塑性断裂分析 ,讨论了弹塑性的随机平衡微分方程和J积分随机分析方法 ,推导了裂纹尺寸对 [B]矩阵和 [Dep]矩阵的影响。编制了弹塑性随机有限元程序 ,并采用数值方法进行了验证。结果表明 ,与Morte carlo方法相比误差为 1 0 5 %。

In general the failures of pressure vessels are dominated by e lasto-plastic parameter named as J -integral. The J -integral parameter was adopted by many codes such as CEGB R6, PD6493 and SAPV95 to assess the str uctures safe ty. In this paper the elasto-plastic fracture analysis was carried out, in whic h the crack size is taken into account as the basic random variable. The stochast ic partial equivalent equation and the stochastic analysis of J -integral we re di scussed. In particular, the partial derivative of and the partial deri vative of [ D \-\{ep\}] were derived. Based on these formulas the elasto-pl astic sto chastic finite element program was performed, and it is shown that the result er ror is about 1.05% which is compared with Morte-carlo method.