Integrated thermal, micro- and macro-mechanical modelling of post-fire flexural behaviour of flame-retarded glass/epoxy composites

This paper presents an integrated modelling approach for the post-thermal exposure flexural behaviour of glass fibre-reinforced (GFR) epoxy composites with/without flame retardants at both material and structural levels. This numerical model incorporates the outcomes from chemical kinetics and heat-mass transfer analyses. The unit cell-based micro-mesoscopic and meso-macroscopic mechanical models have been shown to accurately simulate the mechanical behaviour of GFR epoxy composites at the material level. The post-fire (e.g., composites thermally damaged by exposure to one-sided radiant heating) flexural behaviours of GFR epoxy composites were numerically modelled using finite element (FE) analyses. The predicted residual flexural stiffness for GFR epoxy composites exposed to different transient radiant heating conditions are compared with experimentally-measured post-fire flexural data in order to validate the numerical modelling approach while allowing its accuracy to be assessed. The good agreement between predicted and experimental data demonstrates the accuracy of the integrated numerical model in simulating the post-fire flexural bending of GFR epoxy composites.