变更载荷谱情况下的耐久性分析技术与应用

针对全尺寸飞机结构疲劳(耐久性)试验过程中更改载荷谱情况下对全尺寸结构疲劳试验机(单机)进行耐久性评定的需求,基于耐久性分析的概率断裂力学方法和改进的裂纹萌生方法,提出了综合不同谱下耐久性试验数据集确定描述结构细节原始疲劳质量的当量初始缺陷尺寸分布的方法,给出了载荷谱变更情况下计算各应力区裂纹超越概率的损伤累加方法,从而建立了能够准确预测载荷谱变更情况下结构经济寿命的耐久性评定方法.这种方法已成功应用于某型飞机结构全尺寸试验中更改载荷谱情况的耐久性评定,有着重要的工程应用价值.

Durability analysis technology and application when loading spectrum is altered

In order to satisfy the requirements on durability evaluation of aircraft structure full scale fatigue(durability) testing when loading spectrum is altered,based on probability fracture mechanics approach and improved crack initiation approach of durability analysis,a method was presented to establish equivalent initial flaw size distributing that describes structural detail initial fatigue quality using all durability testing date under different load spectrums,and an accumulated damage method was presented to calculate crack exceeded probability in every stress district when loading spectrum is altered.Then a durability evaluation approach that can exactly predict structure economy life when loading spectrum is altered was presented.It has a great value and has been successfully applied for the durability evaluation of some aircraft structure full scale fatigue testing when loading spectrum is altered.