Research on Calculation Method for Shape Evolution of Surface Crack Propagation in Metal Structures

摘要

Aiming at the phenomenon of fracture failure caused by surface crack propagation in metal structures, by applying the relationship between crack-tip stress intensity factor and energy release rate, according to the equally effective energy release rate of every point on the front ofsurface crack, a novel calculation method for shape evolution of surface crack growth is proposed considering crack closure effects. The functional relationship between shape parameters of surface crack in plate and welding T-joint under fatigue loads is calculated by the novel calculationmethod, and the surface crack propagation shape evolution is simulated by the calculation results. Surface crack growth experiments in plate and welding T-joint are carried out, the experiments results are compared with calculated results. The test results are basically identical with calculationresults, which shows that the method based on energy release rate is effective for calculate the shape evolution of surface crack.