Damage effect of composite sandwich structure under shock wave loading

To investigate the damage effect of composite sandwich structure under shock wave loading，the damage experiment of composite sandwich structure under blast loading was carried out systematically. By studying the response process of the maximum deformation value and plastic deformation value of different composite sandwich structures under blast loading with the change of relative distance, a characterization method that measures the overall deformation of composite sandwich structure is proposed. The damage law of composite sandwich structure under blast loading and the failure mode of front and rear panels and core layer are obtained. Additionally, the causes of overall deformation and local failure of the front and rear panels, as well as the failure mechanism of the core layer, are analyzed. By analysing the relationship between the relative distance and the deformation value, combined with the damage degree of the composite sandwich structure under different relative distance, the results show that the relationship between the maximum deformation value of the sandwich structure and the scaled distance is monotonous. It is reasonable to characterize the damage degree and overall deformation of sandwich structure. Finally, based on the maximum deformation value of the composite sandwich structure, the damage criterion of the composite sandwich structure under blast loading is proposed by using the shock wave overpressure criterion.