Blast Resistance of an Innovative Helmet Liner composed of an Auxetic Lattice Structure

Document Type : Research Article

Author

Faculty of Engineering, Imam Ali University, Tehran, Iran.

10.22060/ajme.2021.19974.5976

Abstract

Helmet liners are employed to prevent or reduce head injuries caused by impact or blast loads. Liners minimize the damage by shock attenuation and absorbing the dynamic energy. In order to improve blast resistance and crashworthiness characteristics of helmet liner under air-blast, in the present study, an innovative structure designed by an arrow-head auxetic lattice structure is suggested to replace the conventional EPS foams usually employed in the liner section. Explicit finite element method is employed to model the innovative helmet structure under blast loading and results are compared with the conventional case based on trend of acceleration, energy absorption, weight, and Head Injury Criteria (HIC) factor. Also, a parametric study is conducted on the effect of lattice structure’s cell size in the protective performance of helmets. Results indicate a great improvement in blast resistance of helmet when the suggested liners are employed so that the HIC number could be decreased by 71% when AH4 configuration is used while the overall energy absorption capacity of helmet is increased about 34% compared to the basic model.

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