Optimisation of an elastomeric pre-buckled honeycomb helmet liner for advanced impact mitigation

Adams, Rhosslyn; Soe, Shwe; Theobald, Peter

Abstract

Advances in computational modelling now offer an efficient route to developing novel helmet liners that could exceed contemporary materials’ performance. Furthermore, the rise of accessible additive manufacturing presents a viable route to achieving otherwise unobtainable material structures. This study leverages an established finite element-based approach to the optimisation of cellular structures for the loading conditions of a typical helmet impact. A novel elastomeric pre-buckled honeycomb structure is adopted and optimised, the performance of which is baselined relative to vinyl nitrile foam under direct and oblique loading conditions. Results demonstrate that a simplified optimisation strategy is scalable to represent the behaviour of a full helmet. Under oblique impact conditions, the optimised pre-buckled honeycomb liner exceeds the contemporary material performance when considering computed kinematic metrics head and rotational injury criterion, by up to 49.9% and 56.6%. Furthermore, when considering tissue-based severity metrics via finite element simulations of a human brain model, maximum principal strain and cumulative strain density measures are reduced by 14.9% and 66.7% when comparing the new material, to baseline.

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2023
• Online Publication Date: Jul 28, 2023
• Publication Date: Sep 30, 2023
• Deposit Date: Jul 22, 2023
• Publicly Available Date: Aug 1, 2023
• Journal: Smart Materials and Structures
• Print ISSN: 0964-1726
• Electronic ISSN: 1361-665X
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 32
• Issue: 9
• Article Number: 095012
• DOI: https://doi.org/10.1088/1361-665x/ace94b
• Keywords: Helmet, traumatic brain injury mitigation, finite element analysis, honeycomb, additive manufacturing
• Public URL: https://uwe-repository.worktribe.com/output/10971679
• Publisher URL: https://iopscience.iop.org/article/10.1088/1361-665X/ace94b