Load-bearing behaviors of sandwich plates with non-uniformly distributed grid cores: Dynamic impact and blast

Sandwich plates with grid-core structures possess extensive applications, and non-uniform grid plates (NUGPs) show enhanced potential under varied loading modes. The current study embarks on an investigation into NUGPs by adjusting the dimensions of transverse and longitudinal grid walls. This comprehensive analysis explores the dynamic responses of these plates when subjected to impact and blast loads, focusing on deformation patterns, damage, and the underlying processes. The findings are illustrated as follows. 1) NUGPs, specifically those with an optimized configuration of grid walls termed the d2 structure, display improved resistance to blast and impact loads compared to their uniformly distributed grid plate counterparts. Notably, designs featuring a less dense grid in the central area yield a more evenly distributed damage pattern under impact loads and a lesser severity of damage from blast loads. 2) The study also reveals that under impact loads, the sandwich structure showcases distinct behaviors through three stages evident in the load-displacement curves: initial localized indentation, followed by overall deformation, and ending with deformation recovery. 3) Moreover, when facing blast loads, the initial response involves rapid plastic deformation of the upper skin, succeeded by compression and buckling of the core. This sequence effectively dissipates energy, acting as a protective shield for the lower skin. 4) The optimized NUGPs design achieves a perfect balance between stiffness and ductility, reducing displacement through adequate stiffness while ensuring the effective absorption of dynamic forces through significant ductility, thus preventing catastrophic failure. This research significantly advances topology optimization for sandwich plates, providing essential insights for designing lightweight structures resilient under various modes. • NUGPs with optimized grid walls offer superior blast/impact resistance over GPs. • Analysis details phased responses to impact/blast, highlighting deformation stages. • Optimized NUGPs balance stiffness and ductility, preventing catastrophic failure.