Session: 02-04-02: Computer Methods and Reduced Order Modeling

Paper Number: 156126

156126 - Impact Analysis of a Composite Combat Helmet Using Structural Metamaterials 

This study explored the innovative use of cellular metamaterials in combat helmets under ballistic loading, marking a significant advancement in this unexplored domain. It stands out as the first investigation to incorporate realistic helmet designs and assess pad systems, thereby pushing the boundaries of current knowledge. All proposed designs successfully satisfied the stringent requirements of the NIJ Standard for Ballistic Helmets, underscoring their practical viability.

Among liner systems, the double arrowhead structure demonstrated exceptional performance, achieving approximately 30% lower Head Injury Criterion (HIC) values than the hexagonal structure of comparable mass and dimensions during direct impacts and over 50% during oblique impacts. For pad systems, the re-entrant and double arrowhead structures reduced HIC values by around 50% relative to hexagonal designs under direct impact. Replacing the full liner with a pad system resulted in a nearly 50% reduction in helmet mass while still achieving notable impact mitigation. Specifically, HIC values decreased by approximately 25% for the hexagonal design and 50% for auxetic structures in direct impacts.

The auxetic structures’ unique free-edge designs enabled densification upon impact, enhancing their impact mitigation capabilities compared to the constrained liner systems. However, while the lightweight pad system excelled in direct impact scenarios, it demonstrated limitations under oblique impacts, showing less favorable rotational injury metrics.

Presenting Author: Zafer Kazanci Queen's University Belfast

Presenting Author Biography: Dr Zafer Kazancı is a Senior Lecturer, Aerospace Engineering Programme Director and Director of the Advanced Composites Research Group (ACRG) at Queen’s University Belfast, UK.