Numerical evaluation of the effect of the weld metal on the constraint factor in bi-metal C(T) specimens

Abstract

The effect of the weld metal on the out-of-plane constraint in C(T) bi-material specimens was studied using the Common Format Equation (CFE) and its associated constraint factor, Ω∗, as a function of the thickness-to-ligament ratio, B/b. The values of Ω∗ for one-material specimens (base metal) and bi-material specimens (base metal plus weld metal) were compared. The presence of weld metal lowers the degree of constraint in the bi-material specimens in relation to the base metal specimens for a given B/b value. This effect is attenuated for deeply cracked specimens, the Ω∗ values being similar for the one-material and the bi-material specimens.