Incremental Damage Formulation and Its Application to Assess IGSCC Growth of Circumferential Cracks in a Tube

Abstract Recent cracking indications in the roll-transition (RT) zone of steam-generator tubes of several pressurized water reactors emphasize the greater need for quantitative assessment of the cracking response, especially for the safe and economic continued operation of the reactors. To address this need, the author recently proposed and examined a strain rate-based incremental damage formulation using the concept of an effective stress. Details of the formulation and its application to the tube cracking phenomenon are presented in this paper. The crack growth model consists of a set of constitutive relations for the material deformation (including creep), an effective stress relation that couples the local and nominal deformation responses and accounts for the crack size and its growth rate, and the corrosion damage relation in terms of the local strain rate and environmental parameters. In this model, the crack initiation and propagation phases do not need to be treated separately; nor is it a requir...