Numerical study on fatigue crack growth of CT specimens treated by laser shot peening

In order to investigate the effect of laser shot peening upon the growth of fatigue cracks,definite element analysis softwares,i.e.,finite element analysis code ABAQUS and MSC.Fatigue were used to simulate the distribution of compressive residual stress,the fatigue life,rate of crack growth and the size of final crack with different laser peening times from one to three on compact tension (CT) specimens of 6061-T6 aluminum alloy.Based on theoretical analysis,the forecasting model of fatigue life for laser shot peening (LSP) process was established.The residual stress field induced by LSP was analyzed with ABAQUS code firstly,and then the stress field model was imported into MSC.Fatigue code for the crack growth analysis.It showed that LSP could effectively inhibit the crack growth,decrease the rate of crack growth as well as the size of final crack,and then the fatigue life was extended.The increase of peening times could increase the effect of LSP to some extent.However,the effect gradually became weak.The results afford a foundation for theoretical analysis and experiments about the effect of laser shot peening upon the growth of fatigue cracks.