Crashworthiness design of GFRP bar reinforced concrete bridge pier subjected to truck collision

This study investigates the failure behavior and post-impact damage of glass fiber reinforced polymer (GFRP) bar reinforced bridge pier under truck collision. The finite element model of a benchmark bridge with its pier reinforced with GFRP bars collided by a medium truck is established using LS-DYNA. The effectiveness of adopted material models and contact algorithm is verified by comparing the experimental and numerical observations of scaled GFRP reinforced concrete columns under horizontal impact loading. The failure analysis results show that the postimpact damage of the composite pier can be classified into four levels, and the shear force at pier bottom is a reasonable index that can represent the dynamic shear capacity of the composite pier. Besides, the influence of design variables on the dynamic shear capacity of the bridge pier is clarified, and a closed-form formula is proposed to predict the dynamic shear capacity based on response surface methodology. Furthermore, kinetic energy-based damage index and damage evaluation approach are developed to forecast the post-impact damage levels of the composite bridge pier. Finally, combining the post-impact performance objectives and damage evaluation approach, a performance-based crashworthiness design framework is developed and validated to provide a basic reference for design consideration of GFRP reinforced concrete bridge pier.