Modeling the inelastic deformation and fracture of polymer composites – Part II: Smeared crack model

This paper describes and validates a new fully three-dimensional smeared crack model to predict the onset and propagation of ply failure mechanisms in polymer composites reinforced by unidirectional fibers. The failure criteria are used to predict not only the onset of the failure mechanisms but also the orientation of the fracture plane. This information is used in a smeared crack model for transverse cracking that imposes a linear softening relation between the traction acting on the fracture planes and the crack opening displacements. The longitudinal failure mechanisms are represented using bi-linear softening relations. The model is validated using off-axis compression tests performed in unidirectional specimens as well as using tensile tests in notched multidirectional laminates. A good correlation between experimental observations and numerical predictions is obtained.

► We propose a three-dimensional smeared crack model to simulate intralaminar fracture in composites.
► Three-dimensional failure criteria are used to predict crack onset and orientation.
► A mixed-mode cohesive law is used to simulate crack propagation under general loading conditions.
► The model predictions show a good correlation with experimental results.