Unified Characterization Model for Prior-corrosion Fatigue Short Crack Propagation Behavior of Aluminum Alloy

Under combination action of corrosive environment and cyclic fatigue loading,cracks will initiate more easily and thus harm the structure safety.The propagation behavior of a corrosion short crack is significantly different from that of a relatively long crack,and the former takes more than 90% of the whole structure fatigue life.A modified elastic-plastic corrosion short crack propagation characterization model was proposed based on the traditional LEFM model and was verified by prior corrosion fatigue experimental results of LD2 aluminum alloy.The results indicated that the modified model was able to characterize both short and long corrosion fatigue crack propagation behavior,which is remarkably of importance for corrosion fatigue life prediction and damage tolerant analysis of aluminum structure.