Analysis of cushion systems for impact protection design of bridges against overheight vehicle collision

Based on several theoretical models of elastic and elastic–plastic impact as well as energy method, a systematic methodology for design analysis of cushion structures for impact protection of bridges against overheight vehicle collision is presented with consideration of the shear-off effect of projectiles and the nonlinear crushing behavior of sandwich cores. Three design criteria based on contact force, deflection, and energy are proposed, and the theoretical models for elastic, elastic–plastic, and after-densification impact including the shear-off effect of projectile are developed to improve the analysis and design of cushion structures against overheight vehicle impact. Realistic analysis of cushion structures is resulted from the above models, and it can be applied to design of cushion structures for the sake of bridge protection from overheight vehicle collision.