复杂结构多裂纹扩展相互影响的研究

INTERACTION AMONG MULTIPLE CRACKS PROPAGATION FOR COMPLEX STRUCTURE

针对多传力路线复杂结构具有多个疲劳源、多条裂纹同时扩展且相互影响的特点,提出一种变柔度方法来考虑多裂纹间的相互影响,并设计专门的双孔板试验验证。应用该方法试算了多钉多层复杂接头全寿命,表明该变柔度方法在工程上是可行的。

In this paper, the interaction among multiple cracks propagation in some complex engineering structures with multi load-path is studied by varying the local flexibility. A method to calculate the variation of local flexibility and to make a sequence of reanalyzing of stress distribution during crack propagation is provided, and a special designing fatigue experiment using a two hole plate specimen with four hole -edge cracks is carried out. The experimental and calculating results are in good agreement, and some useful conclusions about the interaction among multiple cracks propagation are obtained through this special experiment. Finally, this method is used to predict the total life of a complex joint with multi-fastener and multi-layer. The comparison between predicting and experimental results shows further that this method is suitable for engineering practice.