Dynamic response of PLA honeycomb core GFRP sandwich panels with an additively manufactured core: Experimental characterization and numerical blast analysis

This study investigates the transient dynamic response of an additively manufactured polylactic acid (PLA) honeycomb sandwich panel with glass-fiber-reinforced plastic (GFRP) face sheets through experimental characterization and finite element analysis. The PLA honeycomb core was fabricated using fused deposition modelling, while the GFRP face sheets were prepared using the hand lay-up technique. Tensile, flexural, and density tests were conducted to experimentally characterize the material properties used in the numerical model. A finite element model was developed in ANSYS using the experimentally obtained effective properties and was initially assessed against benchmark results reported in the literature. The experimental and numerical displacement–time histories under cantilever harmonic excitation at 500 Hz and 0.2 N showed similar trends for the investigated laboratory condition. A separate numerical calculation was performed to examine the early-time global displacement response under a hypothetical prescribed modified Friedlander pressure pulse using a linear-elastic material representation. The blast analysis showed maximum deformation in the central region of the panel and relatively lower displacement near the supported boundaries. Within the 30 ms simulation window, the panel exhibited a bounded transient displacement response. The blast calculations represent early-time global displacement predictions under the assumption of a linear-elastic material. Failure initiation, progressive stiffness degradation, core crushing, and interfacial separation were not modelled, and energy absorption was not quantified. Accordingly, the calculated histories do not establish retained structural integrity or validated blast-protection performance. The study provides experimental characterization and a laboratory assessment of the global dynamic response of the investigated configuration, along with preliminary elastic calculations under the prescribed pressure pulse.