Modeling fracture of fiber reinforced polymer

In the present paper 3D rate sensitive constitutive model for modeling of laminate composites is presented. The model is formulated within the framework of continuum mechanics based on the principles of irreversible thermodynamics. The matrix (polymer) is modeled using 3D rate sensitive microplane model. For modeling of fibers (glass) a uni-axial constitutive law is employed. The fibers are assumed to be uniformly smeared-out over the matrix. The formulation is based on the assumption of strain compatibility between matrix and fibers. To account for the de-lamination of fibers, the matrix is represented by the periodically distributed bands with non-uniform strength properties over the band width. The input parameters of the model are defined by the mechanical properties of matrix and fibers (elastic properties, strength and fracture energy), the volume content of fibers and by their orientation in 3D space. The model is implemented into a 3D finite element code. To assure mesh objective results, the localization limiter is based on the assumption of constant energy dissipation within each finite element, i.e. the crack band method is used. The performance of the model is shown on one numerical example for specimens loaded in uni-axial tension. It is demonstrated that the proposed model is able to realistically predict the resistance and failure mode of complex fiber-reinforced composite for different orientation of fibers.