Evaluation of in-plane crushing performance of printed randomly polymeric honeycombs filled with foamed concrete

Proper design of cellular structure-based composite could well improve the mechanical properties of the constituent members acting separately. In this study, the novel foamed concrete-filled honeycombs (FCFHs) with tailored geometrical architectures of additively manufactured polymeric honeycombs were developed. The in-plane crushing performance of FCFHs subjected to quasi-static and impact loadings was investigated experimentally and numerically. It was demonstrated that the existence of foamed concrete within honeycomb cells greatly strengthens the collapse resistance of cell walls, and the premature failure of foamed concretes in FCFH is effectively prevented. The shear-dominated failure mode of FCFHs with honeycombs of relatively large cell size or regular configuration or low relative density gradually transforms to a global compression deformation by decreasing cell size or increasing cell irregularity or relative density of honeycomb. Benefiting from the interaction-induced reinforcement between the involved components, the mechanical properties of FCFHs are highly dependent on the mesostructures of honeycomb skeleton. Specially, a decrease of cell size from 5 mm to 3.5 mm yields an increase in the mean crushing strength and the specific energy absorption of FCFHs up to 49.6% and 69.0%, respectively. Further, a numerical model, which was validated against experimental tests, was adopted to study the dynamic behavior of FCFHs. It transpires that the contribution of each component to the energy absorption, relating to the mesoscale deformation mechanism, largely depends on impact velocity. This study aims to provide a promising route to design and optimize lightweight composite structures with high performance.