This work focuses on the finite element analysis (FEA) of a new combat helmet design developed by the Spanish Company FECSA S.A. with the aim of optimizing the final design. The helmet was made of aramid/phenolic resin. Mechanical behavior under impact conditions were analyzed through the experimental Fragment Simulating Projectile (FSP) and Full-Metal Jacketed (FMJ) impact tests on aramid flat plates. From this point, the helmet numerical model, developed using the commercial code ABAQUS/Explicit, was optimized in order to reach the required ballistic limit. Since the aramid composite mechanical properties depends on fiber orientation, a user-defined subroutine VUMAT was developed to simulate the composite behavior under ballistic penetration. For the final validation of the proposed numerical model, experimental impact tests on helmets were performed showing good agreement with the numerical predictions.The authors acknowledge the Ministry of Economy and Competitiveness of Spain under the Project RTC-2015-3887-8 for the financial support of the work
