Impact Test And Crashworthiness Research Of X-shape Sandwich Energy Absorbing Structure

The likelihood of ships ramming a bridge increases with the number of Bridges being built.The sandwich structure is widely used in anti-collision engineering because of its light weight and good crashworthiness.As a new type of sandwich structure,it is necessary to study the energy absorption characteristics and failure modes of the sandwich structure under impact load.In this paper,the dynamic response of x-type sandwich structure under impact load is studied by means of numerical simulation and experimental research.Based on the existing impact test equipment and the existing test conditions,a set of large-scale impact test equipment of sandwich structure was designed to avoid secondary impact,and the feasibility of the test equipment and test scheme was verified by numerical simulation.Then the impact test of the x-type sandwich structure and the tensile test of the material were carried out.The 3d scanning technique is used to obtain the 3d shape of sandwich panel before and after the collision,and then the maximum impact depth is obtained.High speed camera and acceleration sensor are used to obtain and process test data.At the same time,the validity of the numerical model is verified by comparing the numerical simulation with the experimental results.Furthermore,the failure modes of the sandwich structure under different impact shapes,impact positions and impact velocities are analyzed.Based on crashworthiness index,the crashworthiness of sandwich structure was studied.The results show that the panel is the main deformation energy absorbing structure and the sandwich plate is the deformation buffer.It provides some ideas for the design of sandwich structure.Finally,taking xihoumen cross-sea bridge as an example,the multi-stage energydissipating floating anti-collision facilities of steel sandwich composite materials are designed according to the anti-collision characteristics of the bridge.Then the full-scale ship model is used to simulate the process of ship-bridge,ship-anti-collision facilities and bridge collision.The anti-collision facilities of sandwich structure can greatly reduce the ship collision force,and can play a role of buffer energy to protect the bridge.