Murray Colleen M, Mao Min, Park Jungjin, Howard John, Wereley Norman M
Composites Research Laboratory, Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA.
Microsphere Material Solutions LLC, Rockville, MD 20852, USA.
Polymers (Basel). 2023 Aug 9;15(16):3350. doi: 10.3390/polym15163350.
Energy-absorbing materials have extensive applications in aerospace and automotive applications. Research has shown buckling initiators, or triggers, in energy-absorbing tubular structures increase the energy absorbed by encouraging the side panels to fold when loaded out of plane in compression conditions. Additively manufactured TPE honeycombs were designed in this study to include these buckling initiators, which introduced a slight decrease in initial weight, as well as initial stress concentrations, while improving crashworthiness characteristics. The samples with buckling initiators (1BI) showed an increase in crush efficiency when directly compared to their no buckling initiator (0BI) counterparts. The 1BI samples maintained an increased crush efficiency regardless of the strain rate used. The samples with 1BI were able to better equilibrate the peak stress with the plateau stress. These honeycomb samples were found to maintain their crush efficiency, even after multiple rounds of compression testing. The quasi-static 0BI samples experienced a 23.4% decrease in the peak stress after multiple rounds of compression testing, while the 1BI samples saw approximately a 23.0% decrease. The 1BI samples averaged a decrease in crush efficiency of 0.5%, while the 0BI samples saw a decrease in crush efficiency of 5%. As the strain rate increased, the crush efficiency for the 1BI samples showed an increase in performance, with a smaller degradation in crush efficiency over multiple uses. Visco-elastic honeycomb with buckling initiators has a higher energy absorption than samples with no buckling initiators when exposed to multiple impact cycles.
能量吸收材料在航空航天和汽车应用中有着广泛的应用。研究表明，在能量吸收管状结构中，屈曲引发器或触发器通过在压缩条件下使侧面板在平面外加载时发生折叠来增加吸收的能量。本研究设计的增材制造热塑性弹性体蜂窝包含这些屈曲引发器，这导致初始重量略有下降以及初始应力集中，同时提高了抗撞性特征。与没有屈曲引发器（0BI）的对应样品直接比较时，带有屈曲引发器（1BI）的样品的挤压效率有所提高。无论使用何种应变率，1BI样品都保持了提高的挤压效率。带有1BI的样品能够更好地使峰值应力与平台应力达到平衡。这些蜂窝样品即使经过多轮压缩测试后仍能保持其挤压效率。经过多轮压缩测试后，准静态0BI样品的峰值应力下降了23.4%，而1BI样品下降了约23.0%。1BI样品的挤压效率平均下降了0.5%，而0BI样品的挤压效率下降了5%。随着应变率的增加，1BI样品的挤压效率表现出性能提升，在多次使用中挤压效率的下降较小。当暴露于多个冲击循环时，带有屈曲引发器的粘弹性蜂窝比没有屈曲引发器的样品具有更高的能量吸收。
