Hybrid Honeycomb/EPS Foam Liner for Enhanced Energy Orption in Motorcycle Helmets

Authors

  • Mahdi Tabari Faculty of Technical and Engineering, Islamic Azad University, Chalus Branch, Islamic Azad University, Chalus, Mazandaran, Iran.
  • Milad Hemmatnezhad * Faculty of Technical and Engineering, Islamic Azad University, Chalus Branch, Islamic Azad University, Chalus, Mazandaran, Iran. https://orcid.org/0000-0002-8651-3186

https://doi.org/10.48313/mtei.v1i2.51

Abstract

Motorcycle helmets play a critical role in preventing head injuries during road accidents. The energy-orbing liner, typically made of Expanded Polystyrene (EPS) foam, is the key component that dissipates impact kinetic energy through crushing. However, conventional EPS liners exhibit limitations under high-speed and oblique impacts. This study investigates a hybrid energy-orbing structure combining an aluminum honeycomb core with EPS foam, replacing monolithic EPS liners. Quasi-static and dynamic compression tests were conducted on three hybrid configurations with varying honeycomb-to-foam thickness ratios (10/30, 20/20, and 14/26 mm) and EPS densities (40–60 kg/m³). Results were compared with standalone EPS foam and standalone aluminum honeycomb. The aluminum honeycomb alone exhibited the highest energy orption (134 J under impact) but suffers from manufacturing complexity and poor in-plane strength. Hybrid configurations significantly outperformed monolithic EPS foam. Specifically, the hybrid specimen with 20 mm honeycomb and 20 mm EPS (density 60 kg/m³) achieved 89.02 J under impact loading, representing a 40.0% increase over EPS foam alone. Energy orption increased with honeycomb thickness, foam density, and loading rate. Based on these findings, a conceptual helmet design is proposed consisting of an outer composite shell, an intermediate honeycomb layer for primary energy orption, and an inner EPS layer for multidirectional protection. The proposed hybrid liner offers a promising pathway toward next-generation helmets with substantially improved protective performance.

Keywords:

Honeycomb, Expanded polystyrene foam, Energy orption, Motorcycle helmet, Hybrid liner

References

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Published

2024-06-17

Issue

Vol. 1 No. 2 (2024): Mechanical Technology and Engineering Insights (MTEI)

Section

Articles

How to Cite

Tabari, M. ., & Hemmatnezhad, M. . (2024). Hybrid Honeycomb/EPS Foam Liner for Enhanced Energy Orption in Motorcycle Helmets. Mechanical Technology and Engineering Insights, 1(2), 104-110. https://doi.org/10.48313/mtei.v1i2.51

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