Deflection analysis of clamped square sandwich panels with layered-gradient foam cores under blast loading

Graded core sandwich structures have great potential for designing and optimization under special requirement. In the present work, the dynamic response of clamped square sandwich panel (SP) with layered-gradient metal foam core subjected to blast loading was investigated. A new yield criterion of SP with three-layer metal foam core was proposed, and the analytical solutions for maximum deflection over the center point of the panels were obtained. Furthermore, the corresponding results of finite element simulations and experiments were compared to validate the theoretical model. The numerical simulation and experimental results both show good agreements with theoretical predictions. It is shown that the uniform core SP is better than that of the gradient core one and the negative gradient SP is superior to that with positive gradient core in blast resistance for the same equivalent mass. Finally, the minimum mass designs of three-layer SP are stated by constructing geometry optimization diagram according to analytical formula. The theoretical analysis established is of great important in guiding engineering application of sandwich structure with multi-layer core under air-blast loading. •A new yield criterion of the sandwich panel with three-layer metal foam core proposed.•An analytical model of the defection response of graded sandwich panels established.•A good agreement among theoretical, experimental and numerical results is obtained.•The minimum mass design of blast-loaded sandwich panels conducted.