Research On Prediction Method Of Fatigue Life Of Multi-detail Structures

It has been shown that the structures of aging airplanes can be often characterized as WidespreadFatigue Damage（WFD），which has badly threatened the residual strength and the crack growth lifeof airplane structures. For providing a more advanced,ideal and practical damage tolerance analysismethod，the stress intensity factor,reliability life and fatigue life prediction of typical structures areobtained by finite element method in this paper，based on the elastic-plastic and fatigue fracturemechanics.Firstly, focusing on the analysis of the stress intensity factor and conducting the research on thecrack’s position and number of cracks, based on finite element software.And then, predicting thereliability life of typical structures, based on the model of series connection, and comparing with thetest results. At last, predicting the fatigue life of typical structures with cracks, based on stress intensityfactor research results、reliability life results、the net area criterion and Fatigue Crack Propagation RateParis formulation, and comparing with the experimental results.Theories and numerical simulation are used to research the tension-tension fatigue fracture oftypical airplane structures with widespread fatigue damage, and compare the theoretical results withexperimental results. It has shown that the method is believable and practical. This method has a goodcapacity of predication for any structue and can be also applied in engineering.