EXPERIMENTAL AND NUMERICAL ENERGY ABSORPTION STUDY OF ALUMINUM HONEYCOMB STRUCTURE FILLED WITH GRADED AND NONGRADED POLYURETHANE FOAM UNDER IN-PLANE AND OUT-OF-PLANE LOADING

This study aims to investigate the effect of honeycomb structure filled with graded and nongraded polyurethane foam on reaction force during energy absorption under in-plane and out-of-plane loadings. Three types of aluminum AL5052 honeycomb structures without filling, with graded filling and with nongraded filling were manufactured and subjected to quasistatic compression loading. In order to investigate the effect of reaction force and energy absorption capacity, honeycomb cores with different densities were selected. Afterward, the behavior of honeycomb structures was numerically simulated in the ABAQUS software. The results of finite element analysis show that using foam filling in honeycomb structures increases energy absorption. The structures filled with graded foam, shows better performance with the rate of stiffness reduction from impact location compared to those filled with nongraded foam. Energy absorption for graded foam structure occurs at a longer time period comparing to nongraded one. The energy absorption capacity of the structure under out-of-plane loading is much higher than in-plane loading, but its reaction force is very high. The results of empirical tests are greatly similar to that of numerical studies. Therefore, it is possible to use simulation in ABAQUS environment for solving more complex problems.