作者：鲍振宇1, 温垚珂1, 韩瑞国2, 徐诚1, 王亚平1
作者单位：1. 南京理工大学机械工程学院, 江苏 南京 210094;
2. 瞬态冲击技术重点实验室, 北京 102202
关键词：弹道明胶;霍普金森杆;PVDF;高应变率
摘要：
弹道明胶是一种超软材料，其波阻抗很低，采用经典的霍普金森杆测试技术无法获得其在高应变率下的力学特性。该文采用3种基于霍普金森杆的改进方法分别对其动态压缩力学特性进行测试，并对比3种方法的优缺点。实验结果表明：铝杆配合半导体应变片的测试方法对透射信号的提升有限，无法获得弹道明胶的动态力学数据；基于聚偏氟乙稀（polyvinylidene fluoride，PVDF）压电薄膜传感器的方法避免对透射信号的测量，可以获得满意的测试数据；撞击杆直接加载法在小应变阶段的测试结果可信，但在大应变阶段的测试结果无效。综合来看，使用PVDF压电薄膜传感器的测试方法可以较好地获取弹道明胶的动态力学特性。
Study on dynamic mechanical testing method of ballistic gelatin
BAO Zhenyu1, WEN Yaoke1, HAN Ruiguo2, XU Cheng1, WANG Yaping1
1. School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;
2. Science and Technology on Transient Impact Laboratory, Beijing 102202, China
Abstract: As a kind of Ultra-soft materials, ballistic gelatin has very low wave impedance,and therefore their mechanical properties at high strain rates cannot be obtained by using classical split Hopkinson pressure bar testing techniques. In this paper, three methods based on the Hopkinson bar were used to test its dynamic compression mechanical properties. The advantages and disadvantages of the three methods were compared. The method of aluminum bar and semiconductor strain gauges has limited enhancement of transmission signals, and dynamic mechanical data of Ultra-soft materials cannot be obtained. The method of PVDF (polyvinylidene fluoride) piezoelectric film sensor avoids measuring the transmission signal and can obtain satisfactory test data. The impact bar direct strike method and the high-speed photography test method can obtain stronger transmission signals, but require higher sampling frequency for high-speed photography. In conclusion, the PVDF method is recommended for the dynamic mechanical testing of ballistic gelatin.
Keywords: ballistic gelatin;Hopkinson bar;PVDF;high strain rates
2019, 45(9):33-37 收稿日期: 2018-05-23;收到修改稿日期: 2018-09-27
基金项目: 国防科工局稳定支持经费项目（JCKYS2019209C001）；国家自然科学基金（11872215）；国防科技重点实验室基金（6142606020109）
作者简介: 鲍振宇(1994-),男,安徽铜陵市人,硕士研究生,专业方向为软材料动态力学
参考文献
[1] 宋力, 胡时胜. SHPB测试中的均匀性问题及恒应变率[J]. 爆炸与冲击, 2005, 25(3):207-216
[2] 林玉亮, 卢芳云, 卢力. 石英压电晶体在霍普金森压杆实验中的应用[J]. 高压物理学报, 2005, 19(4):299-304
[3] 陈刚, 陶俊林, 陈忠富, 等. SHPB的径向惯性效应修正[J]. 西南科技大学学报, 2008, 23(2):15-18
[4] SLIGTENHORST C V, CRONIN D S, BRODLAND G W. High strain rate compressive properties of bovine muscle tissue determined using a split Hopkinson bar apparatus[J]. Journal of Biomechanics, 2006, 39(10):1852-1858
[5] 刘剑飞, 王正道, 胡时胜. 低阻抗多孔介质材料的SHPB实验技术[J]. 实验力学, 1998(2):218-223
[6] CHEN W, ZHANG B, FORRESTAL M J. A split Hopkinson bar technique for low-impedance materials[J]. Experimental Mechanics, 1999, 39(2):81-85
[7] RICHLER D, RITTEL D. On the testing of the dynamic mechanical properties of soft gelatins[J]. Experimental Mechanics, 2014, 54(5):805-815
[8] 宋力, 胡时胜. 一种用于软材料测试的改进SHPB装置[J]. 实验力学, 2004, 19(4):448-452
[9] NICHOLAS N C, WELSCH J R. Institute for non-lethal defense technologies report:ballistic gelatin[R]. Commonwealth of Pennsylvania:Applied Research Laboratory of PSU, 2004.
[10] 薛本源. 弹道明胶力学性能测试[D]. 南京:南京理工大学, 2018.
[11] 薛本源, 温垚珂, 徐诚,等. 弹道明胶力学性能测试[J]. 医用生物力学, 2018, 33(3):262-266
[12] 王宝珍, 胡时胜. 肌肉类粘弹性超软材料SHPB实验的应力应变均匀性分析[J]. 实验力学, 2011, 26(4):377-382
[13] 郭伟国. PVDF压电薄膜用于Hopkinson压杆测量泡沫金属的动态性能[J]. 实验力学, 2005, 20(4):635-639
[14] ZENCKER U, CLOS R. Limiting conditions for compression testing of flat specimens in the split hopkinson pressure bar[J]. Experimental Mechanics, 1999, 39(4):343-348
