论文部分内容阅读
在飞机结构的设计定型阶段,要综合考虑载荷谱和结构特性的分散评估机群的可靠寿命。为此,进行了某型飞机结构细节的TA15M钛合金模拟试件在3个单机谱下的耐久性试验,断口判读得到主裂纹扩展(a,t)数据,反推得到了当量初始缺陷尺寸(EIFS)。对比分析表明,载荷谱分散对EIFS分布参数无影响,估计得到了通用EIFS分布参数。建立了考虑载荷谱分散的裂纹扩展对数正态随机变量模型及参数估计方法,由此确定裂纹超越概率并进行损伤度评估,建立了综合考虑载荷谱和结构特性分散的概率断裂力学方法(PFMA)。
In the stage of designing and designing the aircraft structure, the reliable life expectancy of the fleet should be evaluated by taking the load spectrum and the structural characteristics into consideration. For this purpose, the durability test of TA15M titanium alloy simulated specimen of a certain aircraft structure under three standalone spectra was carried out. The data of main crack propagation (a, t) were obtained by fracture interpretation and the equivalent initial defect size EIFS). The comparative analysis shows that the dispersion of the load spectrum has no influence on the EIFS distribution parameters, and the general EIFS distribution parameters are estimated. The model of crack growth logarithm normal stochastic variable considering the dispersion of load spectrum and the parameter estimation method are established. Then the probability of crack overrun is determined and the damage degree is evaluated. The probability fracture mechanics method (PFMA) considering load spectrum and structural characteristic dispersion is established ).