Assessment of the shock adsorption properties of bike helmets: a numerical/experimental approach

• Published in: Computer methods in biomechanics and biomedical engineering Vol. 23; no. 5; pp. 169 - 181
• Main Authors: Bocciarelli, Massimiliano, Carvelli, Valter, Mariani, Stefano, Tenni, Matteo
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 03.04.2020; Taylor & Francis Ltd
• Subjects: Absorption; Acceleration; Compression; Compression tests; Computer simulation; Constitutive models; Failure mechanisms; Finite element method; Helmets; impacts; Localization; Mathematical models; numerical modelling; Polycarbonate; Polystyrene; Polystyrene resins; Product design; Protective equipment; Tensile tests; traumatic brain injury (TBI); helmets; numerical modelling; traumatic brain injury (TBI); impacts
• ISSN: 1025-5842; 1476-8259; 1476-8259
• DOI: 10.1080/10255842.2019.1709451

In this paper, a numerical and experimental study of the shock absorption properties of bike helmets is presented. Laboratory compression and tensile tests were carried out on samples of expanded polystyrene (EPS) and polycarbonate (PC), respectively constituting the internal shock absorption layer and the external hard shell of composite helmets. The measured responses of the two materials were then exploited to calibrate the relevant elasto-plastic constitutive models, adopted in full-scale finite element analyses of a helmet subject to standardized impacts. The simulations allowed assessing the time evolution of the acceleration measured inside the headform (according e.g., to EN 1078) and the failure mechanisms of the helmet, if any, as induced by the localization of plastic deformations.