Guey Jason, Rodrigues S, Pullen A, Shaw B, Kieser D C
Defence Technology, Medical Corps, New Zealand Defence Force, Auckland, Auckland, New Zealand.
Department of Orthopaedics, University of Otago, Dunedin, New Zealand.
J R Army Med Corps. 2018 Aug;164(4):277-280. doi: 10.1136/jramc-2018-000924. Epub 2018 Feb 27.
Ballistic gelatin is commonly used as a validated surrogate for soft tissue during terminal ballistic testing. However, the effect of a delay between production and testing of a gelatin mould remains unknown. The aim of this study was to determine any potential effects of ageing on ballistic gelatin.
Depth of penetration (DoP) of 4.5 mm spherical fragment simulating projectiles was ascertained using mixtures of 10%, 11.25% and 20% Type A 250 Bloom ballistic gelatin. Testing was performed daily for 5 days using velocities between 75 and 210 m/s. DoP at day 5 was statistically compared with day 1, and net mass change was recorded daily.
No significant difference was found for DoP observed with time in any of the samples (P>0.05). Spearman correlation was excellent in all moulds. The moulds with known standard calibrations remained in calibration throughout the study period. Mass loss of less than 1% was noted in all samples.
Mass loss was the only quantifiable measure of changes in the blocks with time, but did not correlate with any changes in DoP. This may provide reassurance when undertaking such testing that an inadvertent delay will not significantly alter the penetration properties of the mould. Future research is recommended to determine any potential effect on the mechanical properties of gelatin at higher velocity impacts and whether the calibration corresponds to an adequate simulation under such conditions.
在终端弹道测试中，弹道明胶通常被用作经过验证的软组织替代物。然而，明胶模具生产与测试之间的延迟影响尚不清楚。本研究的目的是确定老化对弹道明胶的任何潜在影响。
使用10%、11.25%和20%的A型250布卢姆弹道明胶混合物，确定4.5毫米球形模拟弹丸的穿透深度（DoP）。每天使用75至210米/秒之间的速度进行测试，持续5天。将第5天的DoP与第1天进行统计学比较，并每天记录净质量变化。
在任何样品中，随时间观察到的DoP均无显著差异（P>0.05）。所有模具中的斯皮尔曼相关性都很好。具有已知标准校准的模具在整个研究期间保持校准状态。所有样品的质量损失均小于1%。
质量损失是块体随时间变化的唯一可量化指标，但与DoP的任何变化均无相关性。这在进行此类测试时可能会让人放心，即意外延迟不会显著改变模具的穿透性能。建议未来进行研究，以确定在更高速度冲击下对明胶机械性能的任何潜在影响，以及在这种条件下校准是否对应于充分的模拟。
