The objective of the present paper is to determine the ability of a transparent polymeric gel, used as a reference material with a mechanical response comparable to that of a human body, to assess less-lethal kinetic energy (LLKE) projectiles. To do this, a consistent measurement method of the dynamic deformation of the gel impacted by a projectile is first of all presented. It relies on high-speed images and image processing routines. Several metrics from the measured gel wall displacement profile are used to investigate experiments. Secondly, repeated impact conditions on various gel blocks confirm that, the proposed material meets the requirements of mechanical consistency, batch-to-batch reproducibility and easy handling. Thirdly, 138 ballistic experiments covering kinetic energies from 10 J up to 300 J are performed, involving commercially available LLKE projectiles of various stiffness. The important dataset is used to perform a statistical analysis through Spearman’s correlation matrix between metrics and projectile parameters. It mainly reveals the need to use a ballistic target to determine the wounding potential of a given projectile rather than kinetic energy density or momentum density. Robust power law mathematical fits describe the relations between three metrics (maximum gel displacement, displacement - rate of displacement-based metric and maximum displaced volume) and kinetic energy density depending on LLKE projectiles’ stiffness. Fourthly, three case reports available in literature and involving LLKE projectiles have been replicated on a gel block. An experimental procedure is proposed based on numerous case reports to give design guidelines in terms of projectile mass, velocity and stiffness. Finally, this original study demonstrates the gel material capabilities to assess LLKE weapons before their field deployment. However, further investigations need to be pursued to propose a relevant injury predictive tool and associated risk curves to law enforcement agencies and regulatory bodies.

本文的目的是确定用作参考材料的透明聚合物凝胶具有与人体相当的机械响应，以评估较小致命动能（LLKE）弹丸的能力。为此，首先提出了一种由弹丸撞击的凝胶的动态变形的一致的测量方法。它依赖于高速图像和图像处理例程。来自测得的凝胶壁位移曲线的几个度量用于研究实验。其次，反复冲击条件对各种凝胶块的影响证实，所提出的材料符合机械一致性，批次间可重复性和易于处理的要求。第三，进行了138次弹道实验，涵盖了从10 J到300 J的动能，涉及各种硬度的市售LLKE射弹。重要的数据集通过Spearman的度量和射弹参数之间的相关矩阵进行统计分析。它主要表明需要使用弹道目标来确定给定弹丸的伤势，而不是动能密度或动量密度。稳健的幂律数学拟合描述了三个度量（最大凝胶位移，位移-基于位移的度量的速率和最大位移体积）与动能密度（取决于LLKE弹丸的刚度）之间的关系。第四，已经在凝胶块上复制了文献中可获得的涉及LLKE射弹的三个案例报告。根据大量案例报告提出了一种实验程序，以给出弹丸质量，速度和刚度方面的设计指导。最后，这项原始研究证明了凝胶材料能够在实地部署LLKE武器之前对其进行评估。但是，需要进一步调查，以向执法机构和监管机构提出相关的伤害预测工具和相关的风险曲线。