School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA.
Neuroimage. 2011 Jan;54 Suppl 1:S45-54. doi: 10.1016/j.neuroimage.2010.05.030. Epub 2010 May 23.
This study aims to characterize the interaction of explosive blast waves through simulated anatomical systems. We have developed physical models and a systematic approach for testing traumatic brain injury (TBI) mechanisms and occurrences. A simplified series of models consisting of spherical poly(methyl methacrylate) (PMMA) shells housing synthetic gelatins as brain simulants have been utilized. A series of experiments was conducted to compare the sensitivity of the system response to mechanical properties of the simulants under high strain-rate explosive blasts. Small explosive charges were directed at the models to produce a realistic blast wave in a scaled laboratory setting. Blast profiles were measured and analyzed to compare system response severity. High-speed shadowgraph imaging captured blast wave interaction with the head model while particle tracking captured internal response for displacement and strain correlation. The results suggest amplification of shock waves inside the head near material interfaces due to impedance mismatches. In addition, significant relative displacement was observed between the interacting materials suggesting large strain values of nearly 5%. Further quantitative results were obtained through shadowgraph imaging of the blasts confirming a separation of time scales between blast interaction and bulk movement. These results lead to a conclusion that primary blast effects may potentially contribute significantly to the occurrence of military associated TBI.
本研究旨在通过模拟解剖系统来描述爆炸冲击波的相互作用。我们已经开发了物理模型和系统方法，用于测试创伤性脑损伤（TBI）的机制和发生。利用了由球形聚甲基丙烯酸甲酯（PMMA）壳组成的简化系列模型，这些壳内装有合成明胶作为脑模拟物。进行了一系列实验，以比较系统对高应变速率爆炸冲击波下模拟物机械性能的敏感性。小爆炸物被引导到模型上，以在比例实验室环境中产生逼真的爆炸波。测量和分析了爆炸波轮廓，以比较系统响应的严重程度。高速阴影成像捕捉到了爆炸波与头部模型的相互作用，而粒子跟踪则捕捉到了内部响应的位移和应变相关性。结果表明，由于阻抗失配，头部内部的冲击波会在材料界面处放大。此外，观察到相互作用材料之间存在显著的相对位移，表明应变值高达近 5%。通过对爆炸的阴影成像进一步获得了定量结果，证实了爆炸相互作用和整体运动之间的时间尺度分离。这些结果得出的结论是，主要爆炸效应可能会对军事相关 TBI 的发生产生重大影响。
