Effect of fibre orientation and thermal exposure on the post‐fire mechanical behaviour of carbon fibre reinforced polymer material

Abstract

This study investigates the influence of fibre orientation and heat flux on the post‐fire (residual) load‐bearing properties of carbon fibre‐reinforced polymer (CFRP) laminates. As a result, a deep insight into the post‐fire load‐bearing response is gained, which is necessary to fully understand and assess the advantages of CFRP laminates containing different fibre orientations for use in load‐bearing structures. Specimens were produced from three CFRP laminates containing different fibre orientations, exposed to varying heat fluxes up to 40 and then loaded in either tension or three‐point bending at ambient room temperature. The study's results have shown that the post‐fire behaviour of CFRP specimens is sensitive to changes in fibre orientation and heat flux. For example, specimens with an anisotropic fibre orientation in tension had the highest tensile load‐bearing capacity, whereas those with bidirectional and multi‐directional fibre orientations demonstrated lower tensile load‐bearing capacities. In bending, however, specimens containing bidirectional and multidirectional fibre orientations had higher load‐bearing capacities than specimens with an anisotropic fibre orientation. Furthermore, the data also shows that exposure to a heat flux reduces the load‐bearing capacity in both the bending and tensile specimens.