【摘要】 将 Paris公式 da/d N =C(ΔK ) n中系数 C和 n视为随机变量 ,采用最小二乘法对 C和 n进行拟合 ,从而得到二者的统计相关性 ,并进一步考察其对疲劳裂纹扩展寿命的影响 .应用概率断裂力学方法 ,对含初始裂纹体的金属材料 (铝合金 )构件的疲劳裂纹扩展寿命进行可靠性分析 .通过算例 ,将 Paris公式中的各个参量全部随机化 ,并预测构件在给定可靠度下的疲劳裂纹扩展寿命更多还原

【Abstract】 Based on the formula presented by Paris , the material coefficient C and n are randomized in this paper. Using the least square method, the statistical correlation between C and n is obtained through the numerical value collocation. Furthermore, the influence of C and n on propagation life of fatigue cracks is discussed. Applying probabilistic fracture mechanics approach (PFMA), the reliability analysis is carried out for helicopter metal material (aluminum alloy)structure having initial cracks. By a example, each parameter is randomized in the formula, and propagation life of fatigue of the structure is prognosticated on the presented reliability.更多还原