Creep damage and stress intensity factor assessment for plane multi-axial and three-dimensional problems

The creep damage and fracture resistance parameter behavior in a plane strain biaxiality loaded plate and 3D finite thickness compact specimen are analyzed by employing damage-evolution equations. The damage model for the fracture of the process zone is represented using a stress-based formulation. Two expressions are proposed to describe the stress-sensitive nature of a multi-axial rupture behavior. Both damage free and defective creeping solids have been studied. The variations in the creep stress and crack-tip governing parameter in terms of the creep In-integral with respect to time and the evolution of creep damage are analyzed using an FE model. The effect of the introduced creep-stress intensity factor as a function of the creep damage and time, loading biaxiality and 3D cracked specimen configuration is discussed in detail through the continuum damage mechanics of the creep-crack growth.