THE USE OF CONTINUUM DAMAGE MECHANICS IN CREEP ANALYSIS FOR DESIGN

The common theme of this paper is the use of Creep Continuum Damage Mechanics (CDM) in design analysis. It is shown how this approach has the capability to model the deformation and rupture behaviour of components which includes simple ligament situations, notched components, cracked members, and butt-welded steam pipes. The following three principal materials requirements are highlighted: (i) deformation behaviour including damage synergisms; (ii) damage kinetics and their relation to physical mechanisms; and (iii) stress state, stress level, and temperature dependence of the deformation, damage, and material failure. New methods are discussed for the determination of multi-axial stress rupture criteria. The use of CDM with mechanisms-based constitutive equations to analyse component behaviour in design is demonstrated.