Stress- and Strain-Based Models of Creep Damage Accumulation

Resumo

In the work, we develop and implement force and deformation models of the strain and damage accumulation rates in creep with the use of the ANSYS finite-element analysis software. Numerical calculations are performed on a plane plate with a rectilinear through crack under biaxial loading and on a three-dimensional compact specimen under eccentric tension. The obtained stress-strain fields are used to calculate the contour I_n integral in the vicinity of the crack tip as well as the distribution of the stress intensity factor at the creep stages. It is found that these parameters behave differently depending on the damage function formulation. It is shown that the creep stress intensity factor can be used as a fracture resistance characteristic that is sensitive to the used model and accumulated damage level, the biaxial loading type and material properties.