Mixed-Mode Fracture Modeled Through a Discrete Cohesive Zone Model-DCZM

Abstract

The Discrete Cohesive Zone Model (DCZM) is proposed to simulate fracture initiation and subsequent growth when material nonlinear effects are significant using the finite element method. Different from the widely-used Continuum Cohesive Zone Model (CCZM) where the cohesive zone model is implemented within continuum type elements and the cohesive law is applied at each integral point, DCZM uses 1D rod type elements and applies the cohesive law as the rod internal force vs. nodal separation. A series of 1D interface elements are placed between node pairs along the intended fracture path to simulate fracture initiation and growth. Dummy nodes are introduced within the DCZM extract information regarding the mesh size and the crack path orientation. To illustrate the DCZM, three popular fracture test configurations (double cantilever beam -DCB, end notched flexure - ENF and mixed mode bending - MMB) are examined, and results are presented that show mesh independence. Good agreement between the present approach and previously published results is shown.