|Title||Attaining regularization length insensitivity in phase-field models of ductile failure|
|Publication Type||Journal Article|
|Year of Publication||2021|
|Authors||B Talamini, MR Tupek, AJ Stershic, T Hu, JW Foulk, JT Ostien, and JE Dolbow|
|Journal||Computer Methods in Applied Mechanics and Engineering|
A cohesive phase-field model of ductile fracture in a finite-deformation setting is presented. The model is based on a free-energy function in which both elastic and plastic work contributions are coupled to damage. Using a strictly variational framework, the field evolution equations, damage kinetics, and flow rule are jointly derived from a scalar least-action principle. Particular emphasis is placed on the use of a rational function for the stress degradation that maintains a fixed effective strength with decreasing regularization length. The model is employed to examine crack growth in pure mode-I problems through the generation of crack growth resistance (J-R) curves. In contrast to alternative models, the current formulation gives rise to J-R curves that are insensitive to the regularization length. Numerical evidence suggests convergence of local fields with respect to diminishing regularization length as well.
|Short Title||Computer Methods in Applied Mechanics and Engineering|