飞机典型结构细节——紧固孔随机裂纹扩展分析

 根据7475T761铝合金犬骨型试样在随机谱载荷作用下的试验结果,采用两种随机裂纹扩展分析的方法,即通用的和解析的分析方法,研究了飞机典型结构细节——紧固孔中疲劳裂纹扩展的概率累积损伤,给出了概率裂纹扩展轨迹、裂纹扩展损伤累积分布及裂纹超出数的概率。试验结果与预测结果的比较表明,两者十分吻合,能满足工程精度的要求,为飞机结构的耐久性和损伤容限评估提供了适用的分析手段。

THE STOCHASTIC CRACK GROWTH ANALYSIS OF A TYPICAL STRUCTURAL DETAIL-FASTENER HOLE OF AIRCRAFT STRUCTURE

Based on the experimental results from dogbone specimens of 7475T761 aluminium alloy under the random spectrum loads, two different stochastic crack growth approaches (i.e., "general" and "analytical" ) are adopted. The probabilistic cumulative damage of the fatigue crack growth in a typical structural detail-fastener hole is studied. The probabilistic crack growth curve, the crack growth damage cumulative distribution and probability of crack exceedance are given. Analytical predictions for both approaches are correlated well with experimental test results. It is satisfatory for the engineering accuracy.These methodologies provide a useful means for the assessment of durability and damage tolerance design for aircraft structures.