Nonlinear Response of a Shallow Sandwich Shell With Compressible Core to Blast Loading

This paper investigates the nonlinear dynamic response of a shallow sandwich shell subject to blast loading with consideration of core compressibility. The shallow shell consists of two laminated composite or metallic face sheets and an orthotropic compressible core. Experimental results and finite element simulations in literature have shown that the core exhibits considerable compressibility when a sandwich panel is subjected to impulse loading. To address this issue properly in the analysis, a new nonlinear compressible core model is proposed in the current work. The system of governing equations is derived by means of Hamilton’s principle in combination with the Reissner–Hellinger’s variational principle. The analytical solution for the simply supported shallow shell is formulated using an extended Galerkin procedure combined with the Laplace transform. Numerical results are presented. These results demonstrate that this advanced sandwich model can capture the transient responses such as the stress shock wave effect and the differences in the transient behaviors of the face sheets and the core when a sandwich shadow shell is subjected to a blast loading. However, in the steady state dynamic stage, all the displacements of the face sheets and the core tend to be identical. This model can be further used to study the energy absorption ability of the core and the effects of different material and geometrical parameters on the behaviors of sandwich structures subject to blast loading.