Analytical–numerical prediction of dynamic response in metallic foam-filled Y-shaped sandwich plates under blast impulse

This study develops an analytical–numerical framework for predicting the dynamic response of fully clamped metallic foam-filled Y-shaped sandwich plates (FYSPs) subjected to idealized blast loading. Based on rigid-plastic idealizations, the structural response is divided into an initial core-compression stage and a subsequent global bending–stretching stage. By formulating the combined compressive resistance of the Y-shaped webs and metallic foam, expressions are derived for the average core compressive strain and the critical impulse associated with core densification. The approximate yield locus of the foam-filled Y-shaped cross-section is then incorporated into a finite-deflection rigid-plastic plate formulation, yielding upper- and lower-bound solutions and a simplified membrane-mode solution. Finite element analysis (FEA) is performed using ABAQUS/Explicit software. The results indicate that the two-stage decoupling assumption for the structural dynamic response is reasonable within the investigated parameter range. As large plastic deformation develops, the analytical predictions progressively approach the numerical results. Parametric analyses indicate that metallic foam strength and density and Y-shaped web thickness significantly affect the structural response, whereas the influence of web angle is comparatively limited. The proposed model provides an analytical basis for evaluating the impulsive response of fully clamped FYSPs.