Abstract

The helmet is the only head protection element for jockey in the falling situation. To date, the standard test for shock absorption capacity of the equestrian helmet consists of only linear impacts and uses outdated injury criteria. Previous studies have shown the existence of normal and tangential components of the impact velocity. The present study presents a new method for the evaluation of equestrian helmet against moderate brain injury coupling experimental tests and numerical simulations. The experimental tests consist in helmeted and instrumented hybrid III dummy head impacting a rigid anvil under linear and oblique impact configurations. These impact conditions allow to highlight the protective effect of the helmet under tangential impact by using an advanced finite element head model and make it possible to estimate the level of brain injury risk by computing the brain shear stress. The method was applied to a set of 7 equestrian helmet models leading to a total of 86 experimental impact tests and 86 numerical simulations of brain response. It was observed that the moderate risk of commotion was ranged from 20% to 90%. It is shown that the most critical impacts are the linear-lateral configuration as well as the oblique impact leading to rotation around the vertical axis, leading to around 85% and 65%, respectively, risks of moderate neurological injuries. Based on this new test method, the study allows us to compare the protective capability of a given equestrian helmet and possibly compare equestrian helmets via a dedicated rating system.

摘要

头盔是骑师跌倒时唯一的头部保护元件。迄今为止，马术头盔减震能力的标准测试仅包括线性冲击，并使用过时的伤害标准。以前的研究表明存在冲击速度的法向和切向分量。本研究提出了一种评估马术头盔对中度脑损伤的耦合实验测试和数值模拟的新方法。实验测试包括在线性和倾斜冲击配置下冲击刚性砧的头盔和仪表混合 III 假人头。这些冲击条件允许通过使用先进的有限元头部模型来突出头盔在切向冲击下的保护效果，并可以通过计算脑剪切应力来估计脑损伤风险水平。该方法应用于一组 7 个马术头盔模型，导致总共 86 个实验冲击测试和 86 个大脑反应数值模拟。据观察，中度骚动风险为 20% 至 90%。结果表明，最关键的影响是线性横向配置以及导致围绕垂直轴旋转的倾斜影响，分别导致约 85% 和 65% 的中度神经损伤风险。基于这种新的测试方法，