Study On Crashworthiness Of Corrugated Core Sandwich Structures Subjected To Ship Collision

The research on the crashworthiness of the new protective structures is always a hot research subject because of the tremendous loss of lives and property caused by the collision accidents on the water.The superior specific strength,specific stiffness and impact resistance of the corrugated sandwiches make them become one of the ideal alternative protective structures of the stiffened plates.What’s more,the filled foam in the sandwich structures can significantly improve the structural crashworthiness.Therefore,in this paper,the crashworthiness of empty triangular corrugated sandwich and PVC foam filled triangular corrugated sandwich were investigated by weight impact experiments and nonlinear numerical calculations.In addition,the crashworthiness of the anti-collision devices based on the corrugated sandwiches and stiffened plates were compared by the LS-DYNA.Firstly,the drop weight impact experiments were carried out to investigate the deformation/failure modes of empty and PVC foam filled triangular corrugated sandwiches.The experiments revealed that corrugated sandwiches behaved several different deformation/failure modes,including the large deformation,plastic buckling and local shear failure.The filling foam could effectively reduce the deformation and damage of the structures although the impact force increased slightly.Secondly,in order to research the dynamic response of empty and PVC foam filled triangular corrugated sandwiches subjected to the local impact load at low impact velocity,the nonlinear numerical calculations were employed and the numerical calculations matched well with the experimental results.The results shown that the deformation process of corrugated sandwich structures could be defined as four stages: Elastic deformation stage,plastic damage stage,compacted stage and rebound stage.The upper panel of the corrugated sandwich was the main energy-absorption components.The presence of PVC filled foam could not only reduce the stress of the structures,but also decrease the damage of the panel,as well as improve the total energy absorption of the structure.On the basis of these,the effects of corrugated core shape,interface connection,structure size parameters and foam filling method on structural deformation/failure modes,impact force and energy absorption were also discussed.Finally,the numerical model of bridge pier,anti-collision devices and impact ship were made by LS-DYNA.It was found that the anti-collision devices could reduce about half of the impact force.In addition,the anti-collision devices made of corrugated sandwich structures suffered smaller deflections than the equivalent anti-collision devices made of stiffened plates.The foam filler had little effects on the deformation and energy absorption of the anti-collision devices under the impact of ship.