Bracq A, Haugou G, Delille R, Lauro F, Roth S, Mauzac O
Laboratory LAMIH UMR 8201 CNRS, University of Valenciennes, 59313 Valenciennes, France.
Laboratory LAMIH UMR 8201 CNRS, University of Valenciennes, 59313 Valenciennes, France.
J Mech Behav Biomed Mater. 2017 Aug;72:138-147. doi: 10.1016/j.jmbbm.2017.04.027. Epub 2017 Apr 29.
The mechanical characterization of a polymer gel used as reference backing material for blunt ballistic impact interpretation is performed at room temperature from quasi-static (0.002s) up to high strain rates (1500s). As very high strain tensile tests (350%) are conducted, an appropriate gripping device and particular strain measurement techniques are used, as well as high strain compressive tests (80%) based on retro lighting imaging. One major challenge is to carry out reliable compressive tests at high strain rates with polymeric split Hopkinson pressure bars using high-speed imaging and specific signal processing software. These mechanical tests provide a primary response to the strain rate dependence of the hyperelastic material behavior. Indeed, the material exhibits a higher stress response when the strain rate increases. Moreover, dynamic compression tests highlight a larger radial strain propagating along specimen axis with higher strain rates. This preliminary study on the characterization of the gel's mechanical behavior, constitutes an interesting step for an evaluation of human surrogate material. The extensive constitutive law can therefore be implemented for numerical simulations, with an aim of impact biomechanics analysis and body armor assessment.
一种用作钝器弹道冲击解释参考背衬材料的聚合物凝胶的力学特性，在室温下从准静态（0.002秒）到高应变率（1500秒）进行测试。由于进行了极高应变拉伸试验（350%），因此使用了合适的夹持装置和特定的应变测量技术，以及基于逆光成像的高应变压缩试验（80%）。一个主要挑战是使用高速成像和特定信号处理软件，通过聚合物分离式霍普金森压杆在高应变率下进行可靠的压缩试验。这些力学试验对超弹性材料行为的应变率依赖性提供了初步响应。实际上，当应变率增加时，材料表现出更高的应力响应。此外，动态压缩试验突出显示，随着应变率的提高，沿试样轴线传播的径向应变更大。这项关于凝胶力学行为表征的初步研究，是评估人体替代材料的一个有趣步骤。因此，可以将广泛的本构定律应用于数值模拟，以进行冲击生物力学分析和防弹衣评估。
