Gosar Aleš, Emri Igor, Klemenc Jernej, Nagode Marko, Oman Simon
Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6, 1000 Ljubljana, Slovenia.
Polymers (Basel). 2023 Mar 4;15(5):1299. doi: 10.3390/polym15051299.
Granular materials promise opportunities for the development of high-performance, lightweight vibration-damping elements that provide a high level of safety and comfort. Presented here is an investigation of the vibration-damping properties of prestressed granular material. The material studied is thermoplastic polyurethane (TPU) in Shore 90A and 75A hardness grades. A method for preparing and testing the vibration-damping properties of tubular specimens filled with TPU granules was developed. A new combined energy parameter was introduced to evaluate the damping performance and weight-to-stiffness ratio. Experimental results show that the material in granular form provides up to 400% better vibration-damping performance as compared to the bulk material. Such improvement is possible by combining both the effect of the pressure-frequency superposition principle at the molecular scale and the effect of the physical interactions between the granules (force-chain network) at the macro scale. The two effects complement each other, with the first effect predominating at high prestress and the second at low prestress. Conditions can be further improved by varying the material of the granules and applying a lubricant that facilitates the granules to reorganize and reconfigure the force-chain network (flowability).
粒状材料为开发高性能、轻质的减振元件带来了机遇，这些元件能提供高水平的安全性和舒适性。本文介绍了对预应力粒状材料减振性能的研究。所研究的材料是邵氏硬度为90A和75A等级的热塑性聚氨酯（TPU）。开发了一种制备和测试填充TPU颗粒的管状试样减振性能的方法。引入了一个新的综合能量参数来评估阻尼性能和重量与刚度比。实验结果表明，与块状材料相比，粒状材料的减振性能提高了400%。通过结合分子尺度上的压力-频率叠加原理的效应和宏观尺度上颗粒之间的物理相互作用（力链网络）的效应，这种改进是可能的。这两种效应相互补充，第一种效应在高预应力下占主导，第二种效应在低预应力下占主导。通过改变颗粒材料并施加有助于颗粒重组和重新配置力链网络（流动性）的润滑剂，可以进一步改善条件。
