Experimental studies on quasi-static axial crushing of additively-manufactured PLA random honeycomb-filled double circular tubes

The Voronoi-based random honeycomb cylindrical shell with specific mesostructures was constructed programmatically and additively manufactured on material of polylactide (PLA). Then, a new PLA random honeycomb-filled double circular tube (PLA-RHFDCT) was proposed. The mechanical performance of the PLA-RHFDCTs in terms of deformation mode, crushing response and energy absorption was studied experimentally by carrying out the quasi-static axial compression loading. A parametric study was performed to evaluate the influence of tube sizes and the mesostructures of honeycomb cores on the crushing resistance and energy absorption capacity of the PLA-RHFDCTs. Results indicate that the cell configuration dominates the deformation modes of PLA honeycomb cylindrical structure. For the PLA-RHFDCTs, the deformation and the bearing capacity are mainly determined by the wall thicknesses of tubes. The introduction of PLA honeycomb core enhances the mechanical performance and affects the localized buckling of the PLA-RHFDCTs due to both the in-plane and out-of-plane crushing resistance of honeycomb core structures. Compared with the parameter of cell irregularity, the relative density of honeycomb cylindrical cores exhibits a higher influence on the energy absorption performance of the PLA-RHFDCTs, though the relatively low crushing strength of PLA honeycomb cylindrical structures.