含多种细节结构的耐久性评定技术研究与应用

Research and Application of Durability Evaluation Technology of Multiple Details Structure

针对飞机结构寿命评定过程中含多种细节结构耐久性评定的需求,基于耐久性分析的概率断裂力学方法,提出了细节型式异同两种情况下结构总的裂纹超越数的计算方法,当细节型式相同时各种细节裂纹超越数直接累加,而细节型式不同时各种细节裂纹超越数加权累加,从而建立了含多种细节结构耐久性评定的一般方法。针对工程上存在大量的含相似细节结构,提出了S-N曲线折算与应力严重系数折算两种相似细节归并的工程方法。特别指出的是,提出的S-N曲线折算方法在保证精度的前提下可以节省较大的试验工作量,有着重要的工程应用价值,已成功应用于中国某型飞机结构定延寿关键部位的耐久性评定。

In order to satisfy the requirements of durability evaluation of multiple details structure in the process of aircraft structure life evaluation, based on the probability fracture mechanics approach of durability analysis, a method is presented to calculate the structural total crack exceedance. Structural total crack exceedance is accumulative total directly of each type of details when the types are of details are same, and it is accumulative total by weight of each type of details when the types of details are different. Accordingly, a durability evaluation approach of multiple details structure is established. Aiming at similar details structure which exist in engineering in large amounts, the S-N curve and stress serious factor approaches that the calculating equivalent relations of similar details in engineering are presented. Especially, the S-N curve approach can save much test work and have enough reliability, and thus have important application value. It has been successfully applied to the durability evaluation of aircraft structure.