An approximate theoretical analysis for clamped cylindrical sandwich shells with metallic foam cores subjected to impulsive loading

A simplified theoretical analysis is developed to predict the dynamic response of clamped cylindrical sandwich shells with aluminum foam cores under air blast loading. In this analytical solution, the whole response of the sandwich shell is split into three sequential stages, similar with the existing three-stage theoretical framework of sandwich structures. In the first stage the blast impulse is assumed to only transfer to the velocity of the front face-sheet. The metallic foam core is considered approximately to be a progressive compressive mode in the second stage, while the back face-sheet is still stationary. In the final stage, the classical monolithic shell theory based on an energy dissipation rate balance approach is employed; and the “upper” and “lower” bounds of the maximum back face-sheet central point deflections and response time are obtained by incorporating a comprehensive circumscribing and inscribing yield loci. A reasonable agreement between the theoretical predictions and experimental results is found for the maximum back face-sheet central point deflection of sandwich shells. The proposed theoretical consideration is significant to guide the engineering applications of cellular metal sandwich structures subjected to air blast loading.