关键词: 固体力学, 断裂, 可靠性, 多裂纹, 一阶二次矩法, 随机有限元法

Abstract: Based on stochastic finite element method and reliability theory, a reliability analysis model for structures with multicrack was presented. Firstly, the expression of stress intensity factors was proposed using the least squares method. Secondly, uncertainties in material parameters, crack length and loading which affect fracture of structures were described as random variables, the reliability index for each crack was obtained by first order reliability method and stochastic finite element method. Finally, the structure with multicracks was taken as a series system composed of all cracks, and the correlation coefficients between failure models were evaluated. The failure probability of the structure was computed by Ditlevsen bounds method. A numerical example was performed for a finite plate with multiple holes and cracks. The result shows that the suggested method is feasible and applicable.

Key words: solidstate mechanics, fracture, reliability, multicrack, first order reliability method, stochastic finite element method