Experimental and numerical study on the dynamical crushing behaviour of sandwich structures with various cell cores under impact load

The present paper aims to figure out the dimensional combination of the core type and gradient distribution of honeycomb shape structure, which could be adopted for the potential applications considering capacity of energy absorption. The sandwich structures with uniform hexagonal, re-entrant hexagonal and gradient hexagonal cell cores are designed and manufactured via 3D-printing technology. The lateral impact tests are conducted to analyze the dynamical responses and damage evolution process of the sandwich structures by using the developed electromagnetic loading (EML) system. The corresponding experimental results are used to validate the numerical modelling approach loading and EML system. The comparative analysis of various design variables, including core type, impact energy, and gradient direction of cellular structures, on the deformation modes, structural compression strength and energy absorption are carried out. Under the same impact energy, the specific energy absorption (SEA) of the gradient hexagonal cell core is 13 % and 46 % larger than that from the uniform hexagonal cell core and re-entrant hexagonal cell core. The findings provide valuable insights into the selection of cellular core configurations for potential protection applications against impact load.