Modelling flexural performance of hollow pultruded FRP profiles

Hollow Pultruded Fibre-Reinforced Polymer (PFRP) profiles, as novel construction material, require further development of design tool to broaden the applications. This paper proposes a combined experimental and numerical methodology as a design tool to investigate the failure modes of these profiles under four-point bending. Two different profiles, each with 10 samples, were tested until failure and were used to validate the numerical model. A finite element model was built based on a fast-convergence incremental approach that suits flexural loading and reduces the computational cost. The validated model was used to study the failure sequence thoroughly and perform an extensive parametric study on the design parameters. Each geometric parameter was studied individually first to determine the relevant levels for each parameter in the full factorial study. A full factorial design of experiment was used to capture the critical parametric interactions with over 81 numerical models. The design rules and recommendation were established for the optimal flexural behaviour of hollow box PFRP profiles to withstand local buckling of the top flange.