干涉配合紧固件的疲劳裂纹扩展寿命分析

AN ANALYSIS OF THE CRACK PROPAGATION LIFE OF THE INTERFERENCE-FITTED FASTENER

利用权函数法给出了含紧固件孔的平板受干涉、双向拉压、各种形式的分布钉载和旁路载荷各种方式的组合作用时孔边穿透裂纹和角裂纹的张开型应力强度因子的数学表达式,可以方便地实施快速积分法求得裂纹扩展寿命。分析了干涉销钉通过填充作用和与孔壁的摩擦对疲劳裂纹扩展寿命的影响。发现钉载及双向载荷条件的不同,干涉增寿效果不同。与实验结果的对比表明方法是有效的。

A method was presented for obtaining stress intensity factors (SIFs) for both through and corner cracks emanating from interference-fitted fastener holes in finite plates subjected to biaxial loading and pin-loading. The SIFs are presented as mathematical formnlas instead of integration, and have the same accuracy as in the case of open and pin-loaded holes. For corner cracks the SIFs are obtained by introducing a geometrical modfication factor. The results are in good agreement with the published results for corner cracks from holes in finite plates subjectei to uniaxial loading when d/B<1.The paper made a further detailed analysis for the effects of different combinations of pin-load, biaxial stress and interference. Some interesting conclusions have been drawn from the analysis: The life of a fastener is sensitive to pin-loading and its distribution, biaxial loadiag, crack shape and interference condition, espicially to the slip condition at the bolt-plate interface.