Fatigue life prediction of the joint plate based on damage mechanics method

Based on damage mechanics theory, a damage evolution equation of fractional form was introduced to study the fatigue life prediction method of the joint plate on a certain aircraft. According to the fatigue test result of standard specimens, parameters in the damage evolution equation were determined. Then, stress distribution of the joint plate was obtained by Ansys finite element software. Results of stress analysis of several typical load situations revealed a linear relationship between load and stress of the dangerous point. Thereby, stress spectrum of the dangerous point was obtained conveniently based on the load spectrum, and appropriate stress plastic amendment was carried. Fatigue life of the joint plate under load spectrum was obtained by closed form solution and numerical solution of damage mechanics, respectively.