Explosion responses of movable z-shaped box bridge: Experimental and numerical investigations

For military bridges, the damage evaluation under close-in explosion is critical to judge their load capacity and service life. In this study, the blast response and damage mechanism of a movable light weight metallic bridge niodel, compnwd of thin-walled skins, x-shaped diaphragms and pin-jointed hinges model, were investigated by close-in explosion experiments and numerical simulations. Quasi-static three-point bending experiments were performed to evaluate the residual bad capacity of the exploded bridge model. The research reveals that the bridge model has overall flexural deformation and complex local deformation patteras. aased on the critical scaled distance, the explosion response can be intuitivelv divided into elastic deformation, plastic deformation, and local fracture. The load capacity of the bridge model is mainly determined by the pin-jointed hinges and the webs. The x-shaped design of diaphragms can reduce the discreteness between the bridge deck and the web, and result in effective energy absorption and good anti-blast performance for the bridge. The study can work as an instruction for the application of movable light-weight bridges under explosion conditions.