Sarron J C, Caillou J P, Da Cunha J, Allain J C, Trameçon A
Délégation Générale pour l'Armement, Direction des Systèmes de Forces et de la Prospective, Départment Technique des Sciences de l'Homme, Armées, France.
J Trauma. 2000 Nov;49(5):923-9. doi: 10.1097/00005373-200011000-00021.
Police and armed forces have helmets that can now stop handgun bullets and even a certain category of rifle bullets. The trend is to increase the ballistic limits of helmets, but injuries caused by nonpenetrating impacts are not well understood. The helmet defeats the projectile and creates a local cone of deformation that impacts the head a second time. The term "rear effects" describes the behind-armor blunt trauma caused by the nonpenetrating impact.
To analyze rear effects on the skull, an experimental study was associated with parametric simulations on a three-dimensional finite element model. Transfer of energy throughout the head was tested on 30 human skulls filled with a silicone gel. The magnitude of contact forces on the skull surface and the pressure levels in the skull were recorded during a reference impact.
A biomedical approach by pathologic findings and radiographs showed very localized fractures. The protection brought by the diploe in the multilayered bone was confirmed and characterized by numerical simulations.
This first step toward a better understanding of the rear effect phenomenon in relation to its consequences on brain tissue will lead to the design of more efficient protections.
警察和武装部队所配备的头盔如今能够抵御手枪子弹，甚至特定类型的步枪子弹。当前的趋势是提高头盔的防弹极限，但对于非穿透性撞击所造成的伤害，人们尚未完全了解。头盔使射弹失效，并形成一个局部变形锥，该变形锥会再次撞击头部。“后效”一词描述的是由非穿透性撞击导致的装甲后钝性创伤。
为了分析对颅骨的后效，一项实验研究与三维有限元模型上的参数模拟相结合。在30个填充硅胶凝胶的人类颅骨上测试了能量在整个头部的传递。在一次参考撞击过程中，记录了颅骨表面的接触力大小以及颅骨内的压力水平。
通过病理检查结果和X光片进行的生物医学方法显示骨折非常局限。板障在多层骨中所提供的保护作用通过数值模拟得到了证实和表征。
这向着更好地理解后效现象及其对脑组织影响迈出的第一步，将促成更高效防护装备的设计。
