Dynamic crushing performance of foam-filled periodic hybrid cellular structures

Abstract

To achieve excellent dynamic crushing performance, an attractive foam-filled periodic hybrid cellular (F-PHC) structure containing both hexagonal and re-entrant cells was designed and fabricated. Dynamic crushing experiments for foam-filled PHC structures were carried out using a direct impact Kolsky bar testing system. Reliable numerical simulations using both finite element method and smoothed particle hydrodynamics method were developed to analyze the dynamic crushing responses of F-PHC structures in the full range of deformation processes. Effects of inertia, strain-rate sensitivity, cell number, and impact velocity were evaluated. The results show that the dynamic plateau stresses of periodic hybrid cellular structures can be substantially enhanced by filling foams. The dynamic crushing response of F-PHC structure is very susceptible to impact velocity due to inertia effect. Compared with foam-filled hexagonal honeycomb and foam-filled re-entrant honeycomb structures, F-PHC structures exhibited superior dynamic crushing performances, including smoother and longer dynamic plateau stresses, more uniform deformation distributions, and much more stable deformation processes. Moreover, F-PHC structures exhibited much lower dynamic initial peak stresses at the rear face. This study provides a fascinating design idea and shines light on attractive F-PHC structures with a promising application prospect in the field of impact protection.