基于应力严重系数和概率断裂力学的耐久性分析方法

Advanced Durability Analysis Method Based on Stress Serious Factor and Probabilistic Fracture Mechanism Approach

将应力严重系数和概率断裂力学结合起来,提出一种新的连接件耐久性分析方法。在新方法中,假设结构细节的原始疲劳质量不受形状、工艺参数和装配状态等影响,而只与材料的缺陷如气孔、夹杂等有关。在此基础上,建立应力严重系数与裂纹扩展速率的关系以确定不同连接件的裂纹扩展寿命。由于结构的原始疲劳质量只和材料缺陷相关,而与结构形式等无关,故新方法不需要大量的试验数据,可节省大量的费用和时间。对某连接件的试验和分析验证了该方法的可行性和准确性。

A new durability analysis method for joint was presented with integration of probabilistic fracture mechanics into stress serious factor （SSF）. In the new method, it was assumed that initial fatigue quality （IFQ） of structure details was not relevant to their configurations, process variables, assembling state,etc. , but material flaws, such as pores and inclusions. Based on the hypothesis, the relationship between SSF and crack growth rate was established, which could predict crack propagation life of different structure details. Since IFQ was only correlative with material flaws and had nothing to do with structure configuration and so on, the new method is independent of tests and saves expenses and time. Examples show that the presented method is feasible and the predicted result is credible.