Rate dependent constitutive modelling of laminated FRP composites degraded by fire

A constitutive theory is proposed for FRP laminated composite materials that is designed to account for both temperature and strain rate dependent response, such as would occur during, and after, exposure to the elevated temperatures due to fire. The theory is physically based, and in particular, is based on a kinematical framework fixed on the fabric laminates; full accounting of laminate reorientation and anisotropic response is thus achieved. The theory is numerically implemented and FEM analysis of compressive deformation of a sandwich panel, given as an example, demonstrates how common material failure modes such as kinking are naturally included in the theory and in analyses using the theory. The theory accounts for finite strains and thus the extent of deformation is arbitrary. The theory and its numerical implementation are designed specifically to perform numerical analysis of structural response of FRP structures subject to fire degradation.