Numerical and experimental validation of the static performance of a full-scale flax fiber-polyester composite bridge model to support the design of an innovative footbridge

•Natural fibers production requires less energy compared to synthetic fibers. This can favor sustainability and promote a shift towards more environmentally friendly construction materials.•A design methodology was developed to assess and overcome uncertainties due to the lack of design guidelines for flax composites for load-bearing purposes.•Two full-scale models are manufactured for production control and mechanical evaluation.•The mechanical model was equipped with 16 embedded fiber-optic Bragg grating (FBG) sensors. A static load test on the mechanical model was designed to replicate the effect of the crowd load for the target footbridge.•Accurate numerical analyses were performed using ABAQUS Standard. Strains and displacements were compared with experimental results for calibration. A good agreement was reached and it was instrumental in the design phases of the innovative footbridge. This paper deals with the numerical and experimental analysis of a large-scale footbridge model made of flax fiber-reinforced polyester composite. The goal of this work was to support the design of the 15 m span flax-polyester footbridge installed at the Floriade Expo 2022 in Almere, the Netherlands. The model stacking sequence, thicknesses, material, and vacuum infusion technology are identical to those of the footbridge. For the numerical analysis, a multi-layered laminate was modeled using ABAQUS with a composite layup and continuous shell elements. The model was equipped with 16 embedded fiber-optic Bragg grating (FBG) sensors for strain sensing and mechanical evaluation. The specimen was subjected to monotonic loading and unloading. Numerical results were compared with those obtained from the load test. The good agreement revealed the correctness of the assumptions. This study provides a design methodology based on numerical and experimental investigation, to overcome uncertainties derived from the application of this innovative material for load-bearing applications in footbridges.