Stress strain analysis of notched specimen based on material property gradient

The stress strain at notch root of round specimen with material property gradient were analysed with elasto-plastic finite element analysis, based on the hardness value obtained from spot welds heat affect zone. Material cyclic strength and fatigue strength coefficient are assumed to be proportional to hardness distribution according Eleiche's conclusion. A set of finite element models was established with material gradient, notches in each model were in different material zone. Elasto-plastic analyses were carried for notch stress strain distribution under different loading levels. Material gradient on life prediction were analysed with local stress strain approach.