MODELING OF FRACTURE AND CRACK-GROWTH IN WELDS OPERATING AT ELEVATED-TEMPERATURES

This paper critically examines the fundamental limitations of the avai lable nonlinear fracture mechanics based models and procedures for pre dicting fracture and crack growth behavior in structural welds. It is shown that the weld fracture and crack growth data show significantly more scatter than the same data in homogeneous materials. The data sca tter is linked to heterogeneity in the microstructure of the weld and the resulting differences in the deformation properties of the weld re gion causing cracks to meander from their expected path. Some prelimin ary ideas for dealing with this scatter are proposed and recommendatio ns for future work in this area are also made.