Low velocity impact resistance of multilayer composite structures for mitigating acceleration

In this manuscript the low velocity impact resistance of a novel multilayered energy absorbing structure was studied and compared to the materials used in US Army Advanced Combat Helmets. We investigate the dynamic performance of 3D printed lattice structures sandwiched between carbon fiber composites and Kevlar fabrics to develop helmets that are lighter and have better blast protection. The energy absorbed by the sandwich structure was recorded based on the difference in acceleration between the top impacted surface and the base of the structure. A multi degree of freedom non-linear spring mass model was used to predict the response of the multilayer sandwich structures. Nonlinear stiffness values were determined through compression experiments. A good agreement between the model and the experiment at the measured boundary allows for better understanding of the material layers and provides a modeling framework for future predictions and optimization efforts. This study provides insights into the use of digitally 3D printed cellular materials, carbon fiber composites, and Kevlar fabrics to provide superior impact performance at a lighter weight compared to existing helmet systems.