Design and simulation of innovative foam-filled Lattice Composite Bumper System for bridge protection in ship collisions

In this paper, an innovative Foam-filled Lattice Composite Bumper System (FLCBS) with fiber-reinforced polymer (FRP) skins and a foam-web core is proposed as protective structures for bridge piers against ship collision. FLCBS consists of FRP face sheets, FRP lattice webs and polyurethane (PU) foam cores, which can be manufactured at the same time by vacuum assisted resin infusion process (VARIP). FLCBS exhibits good energy-absorbing and highly designable properties. The design, performance evaluation, manufacture and installation of FLCBS for a real prestressed concrete continuous girder bridge were introduced. A detailed numerical model for performance evaluation was developed with the explicit finite element (FE) software package ANSYS/LS-DYNA. An experimental study of two foam-filled lattice composite panels under low-velocity impact was conducted to verify the numerical model for FLCBS. The corresponding FE models of the composite panels generally showed good agreement, compared to the impact load history and mid-span deflection history of experimental results. Based on the validated numerical model, both head-on collision cases and lateral collision cases with and without FLCBS were investigated. Simulation of different impact angles, velocities and locations were carried out. Numerical results indicate the obvious advantages of FLCBS by comparing peak impact force and impact duration. Significantly decrement of the peak impact force and effectively prolonged impact process indicate the superior performance of FLCBS. The modular fabrication and replacement, easy and time-efficient installation and highly designable structure make FLCBS very attractive as bridge protection in ship collisions.