Abstract:Based on macroscopic and microscopic analyses of fracture surface of lap joints at different corrosive damage, the influence regularity of fretting on fatigue life for lap joints is obtained. The influence coeffici ent β is introduced to modify the effect of fretting on the stress intensity factor of hole-edge crack of lap joints. Since different crack nucleation sites are associated with different corrosion time, two different fatigue life models are presented considering th e effect of fretting. The results show that the interaction of corrosive and fretting results in more life reducing. For un-corroded and slightly corroded specimens, the cracks usually originate fro m the bolt body region of bolt hole near the countersink region and the fretting damage plays a dominant role. For seriously corroded specimens, the cracks usually originate from the interface of hole wall and contact surface, and the corrosive damage plays a dominant role. Th e results of fatigue life prediction coincide with that of fatigue experiment,considering fretting effect, and the models are more reasonable.