A THERMODYNAMICALLY CONSISTENT PHASE FIELD FRAMEWORK FOR ANISOTROPIC DAMAGE PROPAGATION

Abstract

MANY PHASE FIELD FORMULATIONS HAVE BEEN DEVELOPED TO SIMULATE DAMAGE EVOLUTION TAKING INTO ACCOUNT DIFFERENT PHENOMENA SUCH AS PLASTICITY, LARGE DEFORMATION, ANISOTROPY AND FRACTURE BEHAVIOR OF MATERIALS. IN THE PRESENT WORK, A THERMODYNAMIC CONSISTENT DAMAGE PHASE FIELD FORMULATION IS ADAPTED TO INCLUDE THE EFFECT OF PREFERENTIAL CLEAVAGE PLANES IN THE DAMAGE EVOLUTION. A PHASE FIELD DAMAGE SCALAR VARIABLE IS ASSOCIATED WITH EACH PREDEFINED PREFERENTIAL DIRECTION OF CRACK PROPAGATION. ANY OTHER POSSIBLE DIFFERENT DIRECTION IS PENALIZED BY A PARAMETER (BETA ≫ 1) THAT REPRESENTS THE DEGREE OF ANISOTROPY OF THE FRACTURE. BY DEFINING BETA = 0, THE ISOTROPIC CASE IS RECOVERED. IN CASE OF MORE THAN ONE PREFERENTIAL DIRECTION, THE MATERIAL IS CONSIDERED TOTALLY FRACTURED WHEN ONE OF THE DAMAGE VARIABLES REACHES ONE. THE SIMULATIONS SHOWED THAT THE MODEL CAN REPRODUCE THE EXPECTED CRACK PROPAGATION PATTERN FOR MATERIALS WITH ONE AND TWO PREFERENTIAL DIRECTIONS. THE MODEL WAS SUCCESSFUL IN SIMULATING A ZIGZAG CRACK PATTERN COMMONLY OBTAINED IN DOUBLE CANTILEVER BEAM STUDIES OF SPINEL CRYSTALS.