Out-of-plane static crushing of thin-walled honeycomb structures. Numerical and experimental investigation

Aim of presented study was to compare plateau stress in honeycomb structures under out-of-plane load calculated using Wierzbicki formula with numerical simulations validated using experimental trials. ALUBOND® Alucore honeycomb structure was examined. The results of theoretical, experimental and numerical investigation are reported. Two methods of modeling core behavior were evaluated using simulations. Full core geometry and simplified Y-shaped element were analyzed. Both approaches were compared with experimental out-of-plane compression tests. Aim of the study was to determine the influence of core geometrical parameters on obtained plateau stress value. Various foil thicknesses and cell sizes were studied numerically. The results showed, that initial and final deformation mode strongly depends on the geometry of the honeycomb structure. Force required to crush the core grew with increase of wall thickness, and decreased with increase of cell size. Calculations were performed using an implicit integration scheme implemented in the LS-DYNA software. Research showed the presence of plateau relationship between stress and geometric dimensions and structure response. Good agreement between results obtained by all methods was achieved. Basing on the results, conclusions concerning modeling honeycomb materials were drawn.