Study on fracture transferability from compact type specimen to pipe for 316LN stainless steel

摘要

The transferability of continuum damage parameters for ductile fracture from CT specimen to pipe has been investigated for 316LN stainless steel. The authors have earlier established crack initiation stress and crack evolution energy as damage parameters for 316LN SS, based on coupled experimental and numerical analysis. Using these fracture parameters, XFEM crack growth simulations were carried out for through-wall circumferentially cracked straight pipes of 80NB diameter. To verify the applicability of damage parameters for various crack geometries, the stress triaxiality ahead of a growing crack in CT specimen and through wall crack in pipes has been assessed. The average triaxiality for CT specimen is 1.25 and for the pipes, it varies from 0.4 to 0.62 depending on initial through wall crack size. The predicted maximum load, load-displacement response, crack growth and pipe ovality are compared with the experimental results.