中文摘要：

对含多处损伤（Multiple Side Damage,MSD）宽板搭接件做了等幅疲劳试验和断口分析,得到搭接件的疲劳寿命和孔边MSD裂纹的形成特点、裂纹前沿形状及扩展历程。结果表明,搭接件的疲劳破坏具有一定的隐蔽性,其疲劳寿命的绝大部分消耗在螺栓头下裂纹扩展阶段,当孔间裂纹出现首次连通时,搭接件剩余寿命约为总寿命的0.7%~9.4%。基于有限元软件FRANC2D/L和裂纹扩展分析软件AFGROW,建立了考虑钉载、第二弯矩和孔间裂纹干涉等影响因素的含MSD宽板搭接件疲劳寿命计算模型,并对孔边多裂纹的扩展寿命进行了计算分析。计算结果与试验结果的对比表明,该文所建寿命计算模型具有一定的精度,能满足工程需要,计算结果和结论可作为该类结构损伤容限设计的参考依据。

英文摘要：

The fatigue tests of wide bolted lap joints with MSD were carried out under constant amplitude loading, and fracaxre surfaces were examinated. The fatigue lives of the specimens and, MSD initiation characteristic, crack front shape, and growth course were determined. The results show that the cracks of lap joints are not easy to be founded. The crack initiation stage and early crack growth （up to visible cracks） cover the major part of the fatigue life. When the crack was linked up for the first time, the residual lives are about 0.7%-9.4% of total fatigue life. Based on FRANC2D/L and AFGROW, a life predictive model for lap joints accounted for fastener load and, secondary bending, interference of cracks was developed to calculate the growth lives of MSD cracks. The results show that the results produced by using the life predictive model of lap joints with MSD have a close agreement with experimental results. The simulated results may be serving as a reference for damage tolerance design of the similar structures.