Investigation of 316L stainless steel sandwich honeycomb structure subjected to near-field blast loading

This study investigates the near-field blast resistance of 316L stainless steel honeycomb sandwich structures (HSS) manufactured via selective laser melting (SLM), with a PVC foam-filled honeycomb sandwich structure (FHSS) designed for improved performance. Near-field blast experiments were carried out on specimens at a scaled distance of 0.1315 m/kg 1 / 3 . A numerical model using the S-ALE algorithm in LS-DYNA was developed to simulate the dynamic response and plastic energy distribution. Under blast loading, trident-shaped cracks appear on the front face sheets of both FHSS and HSS, with shorter cracks in FHSS. The numerical model accurately reproduces the deformation, core buckling and crack initiation observed in experiments. SEM reveals distinct melting morphologies on fracture surfaces induced by the explosion fireball. The back-face deflection of FHSS is 15.6 mm, versus 17.5 mm for HSS and 18.1 mm for the solid plate with equal areal density, confirming its superior blast resistance. The numerical-experimental errors are all below 3%. The core layer dominates energy absorption, with that of FHSS contributing 56.5% of the total plastic deformation energy. Foam filling effectively enhances the blast resistance of SLM-fabricated HSS.