Investigation of retention and padding system influence on the backface deformation of helmets

头盔的保持系统对其在冲击下的性能是不可或缺的，特别是对于将**受到弹道冲击的头盔。头盔的背面变形必须保持在最小，因为过度的变形会导致头骨骨折。泡沫填充与内部**保持系统结合使用，以保持头盔的定位，但这增加了头盔系统的体积，**由此产生的惯性会增加短期和长期的健康问题。优化的头盔系统将**具有高弹道极限以阻止弹道威胁，同时将背面变形特征降至最低，**减少撞击过程中向佩戴者头部传递的应力，提供防止碰撞和坠落的保护**，同时为佩戴者提供舒适性。**在这个拟议的项目中，我们将研究头盔内保持系统和泡沫填充**与修订的军用头盔系统的背面变形之间的关系。**泡沫的材料特性将被测量并实施到LSDYNA模型中，该模型可用于优化**头盔的设计。我们将利用一种独特的X射线摄影系统来确定**泡沫、保持系统和头盔变形之间的相互作用。该项目的计算部分将**看到为LSDYNA头盔模型实施的泡沫收集的应力-应变数据，作为**验证头盔性能预测的一种手段，头盔性能预测在头盔设计中被广泛使用。这项研究工作将有助于指导未来军用头盔的设计。

The retention system of a helmet is integral to its performance under impact, particularly for a helmet that will**be subjected to ballistic impact. The backface deformation within the helmet must be kept to a minimum, since**extensive deformation will lead to skull fracture. Foam padding is used in combination with an internal**retention system to maintain the positioning of the helmet, however this adds to the bulk of the helmet system,**the inertia from which can add to near- and long- term health concerns. An optimized helmet system would**have a high ballistic limit to stop ballistic threats while minimizing the backface deformation signature,**reducing stress transfer to the head of the wearer during impact, providing protection from bumps and falls, all**while providing comfort to the wearer.**In this proposed project we will investigate the relationship between retention systems and foam padding**within a helmet to the backface deformation of Revision Military helmet systems. The material properties of**the foams will be measured and implemented into a LSDYNA model that can be used to optimize the design of**the helmets. We will make use of a unique x-ray cinematography system to determine the interplay between the**foam, retention system, and the deformation of the helmet. The computational component to the project will**see stress-strain data collected for foams implemented into a helmet model in LSDYNA as a means of**validating the predictions of helmet performance, which are used extensively in the design of helmets. This**research effort will help to guide the future design of helmets with Revision Military.