Phase Field Based Cohesive Zone Fracture Approach to Model Anisotropic Effect and Interface Fracture in Fiber Reinforced Polymer Composites

Document Type

Conference Proceeding

Publication Date



Department of Mechanical Engineering-Engineering Mechanics


Among multiple damage mechanisms in fiber reinforced polymer composites (FRPCs), delamination is the major failure mode that occurs very often due to low interlaminar strength of these materials. Prediction of this failure mode through computational modeling is not straight forward. In this work we aim to use the phase field fracture method (PFF) to model interfacial fracture in FRPCs. In PFF, the crack is assumed as a diffused entity rather than discrete discontinuities. In the present work, a unified phase field based cohesive zone model (PF-CZM) has been utilized to characterize the interlaminar fracture of carbon fiber reinforced epoxy composite. A Double cantilever beam (DCB) geometry has been simulated for 0? fiber orientation to determine mode I interfacial fracture toughness. To meet the requirement, two laminas of unidirectional FRP were bonded together using an adhesive (resin rich region) for different adhesive layer thicknesses and the corresponding energy release rates are computed. The area method suggested by Whitney [1982] was used to measure the energy release rate (R-curve). The results show different GI values for different thickness of adhesive layer and remains within a specified limit. The peak load is also different for different thicknesses of adhesive. Prior to the DCB simulations, open hole tension (OHT) simulations for different fiber orientations (0?, 45? and 90?) were also performed for carbon-fiber reinforced epoxy composite to validate the PF-CZM model prediction with the experimental data available in literature.

Publication Title

Proceedings of the American Society for Composites - 37th Technical Conference, ASC 2022