Determination of Fracture Characteristics of Nuclear Weld Using Modified GTN Model

Abstract

Ductile fracture is associated with three basic processes i.e. void nucleation, growth and coalescence. The model which, incorporate these features into the constitutive equations of the material, are called continuum damage mechanics models. These are able to describe the physical effect of constraint on the fracture resistance of material in a natural way. In this work the model introduced by Gurson and modified by Tvergaard and Needleman has been implemented in an in-house finite element code MADAM. The material that is studied is SS 308L Weld filler and SS 309L Buttering. The two parameter approaches of fracture mechanics are discussed; also the J-R curve is determined for different cracked specimen, e.g. CT specimen, TPB specimens, from the analysis by finite element code MADAM and compared with the experimental curves. Also the various set of Gurson parameter is evaluated by comparison of experimental and analytical J-R curve to determine the fracture characteristics of nuclear welds.