Werling Tobias, Baumann Georg, Feist Florian, Sinz Wolfgang, Ellersdorfer Christian
Mercedes-Benz AG, HPC X631, 71059 Sindelfingen, Germany.
VSI-Institute of Vehicle Safety, University of Technology Graz, Inffeldgasse 23/I, 8010 Graz, Austria.
Materials (Basel). 2021 Oct 22;14(21):6320. doi: 10.3390/ma14216320.
High-voltage busbars are important electrical components in today's electric vehicle battery systems. Mechanical deformations in the event of a vehicle crash could lead to electrical busbar failure and hazardous situations that pose a threat to people and surroundings. In order to ensure a safe application of busbars, this study investigated their mechanical behavior under high strain rate loading using a split Hopkinson pressure bar. Two different types of high-voltage busbars, consisting of a polyamide 12 and a glass-fiber-reinforced (30%) polyamide 6 insulation layer, were tested. Additionally, the test setup included a 1000 V electrical short circuit measurement to link the electrical with the mechanical failure. It was found that the polyamide 12 insulated busbars' safety regarding insulation failure increases at high loading speed compared to quasi-static measurements. On the contrary, the fiber-reinforced polyamide 6 insulated busbar revealed highly brittle material behavior leading to reduced bearable loads and intrusions. Finally, the split Hopkinson pressure bar tests were simulated. Existing material models for the thermoplastics were complemented with an optimized generalized incremental stress state-dependent model (GISSMO) with strain rate dependency. A good agreement with the experimental behavior was achieved, although the absence of viscoelasticity in the underlying material models was notable.
高压母线是当今电动汽车电池系统中的重要电气部件。车辆碰撞时的机械变形可能导致电气母线故障，并引发对人员和周围环境构成威胁的危险情况。为了确保母线的安全应用，本研究使用分离式霍普金森压杆研究了它们在高应变率载荷下的力学行为。测试了两种不同类型的高压母线，一种由聚酰胺12制成，另一种由玻璃纤维增强（30%）聚酰胺6绝缘层制成。此外，测试装置还包括1000V电气短路测量，以将电气故障与机械故障联系起来。研究发现，与准静态测量相比，聚酰胺12绝缘母线在高加载速度下绝缘失效的安全性有所提高。相反，纤维增强聚酰胺6绝缘母线表现出高度脆性的材料行为，导致可承受载荷和侵入量降低。最后，对分离式霍普金森压杆试验进行了模拟。通过具有应变率依赖性的优化广义增量应力状态相关模型（GISSMO）对现有的热塑性材料模型进行了补充。尽管基础材料模型中没有粘弹性，但模拟结果与实验行为取得了良好的一致性。
