Detail stress analysis and fatigue crack initiation life prediction of riveted joint

A simplified mechanical model is established to simulate the complicated rivet joint structure and finite element software is applied to the detail analysis of above model. Then the principle of conservative integral of damage mechanics is utilized to obtain the concentrated stress expressions with damage coupling effect. On the base of above expressions, the analytical relation between the crack initiation life and the concentrated stress without damage coupling effect is built by the damage evolution equation which is set up on the basis of the thermodynamics laws and expressed as a function of damage driving force. Further more, according to the median fatigue curves of some standard specimens made of certain material, the material parameters in the damage evolution equation is fitted and the life prediction method is verified by the median fatigue curves of other standard specimens for the same material. At last, the crack initiation lives with different serviceable probabilities are predicted for the critical parts of certain civil aircraft fuselage.