Anisotropic elasto-viscoplastic damage model for glass-fiber-reinforced polyurethane foam

The aim of the present study was to propose a unified anisotropic elasto-viscoplastic damage model and computational analysis method for predicting the damage growth and material behavior of initially anisotropic glass-fiber-reinforced polyurethane foam (RPUF). A plasticity damage mechanism-based mechanical model with no yield surface is introduced. To consider the microcrack closure effect according to different loading directions, two types of elasto-viscoplastic damage models were developed. The developed models were transformed into the implicit form and implemented in an ABAQUS user-defined material subroutine for the application of finite elements. Finally, the simulation results were compared with a series of tensile and compressive test results on RPUF to validate the proposed model and computation.