An analysis of creep deformation parameters. Part 1: background

Parameters for the correlation of creep deformation and crack extension behavior are developed from principles that assume the commonality of all deformation forms. The assumption is made that the relationship between the force, crack length and deformation parameters has a separated format that has common features for of all types of deformation. This allows the use of parameter forms developed for elasticity and plasticity to be used creep deformation. Creep deformation parameters are developed based on C∗, Ct and on the δ5 formats. These creep cracking parameters can be used to predict residual life in structural components with crack-like defects that operate in the high temperature creep deformation regime. The forms proposed for some of these parameters are experimentally evaluated in a Part 2 paper.