Strain Rate Dependence of Fatigue Crack Propagation and Initiation

摘要

Present study made clear the effect of stress frequency on fatigue crack propagation and initiation of visco-plastic materials by following experiments and FEM analysis. (1) Evaluation of strain rate dependence of material, (2) Making clear the effect of variation of loading frequency on fatigue crack initiation life and propagation rate by fatigue test and measurement of striation on fracture surface by scanning electron microscope(SEM), (3) FEM elasto/visco-plastic analysis at stress concentration part and propagating crack tip, (4) Comparison of the experimental results with the calculation ones by FEM, and propose a evaluation's parameter of effect of stress frequency on fatigue crack initiation and propagation.