Zhao Zeming, Wei Kai, Ding Wenhao, Cheng Fang, Wang Ping
Ministry of Education Key Laboratory of High-Speed Railway Engineering, Southwest Jiaotong University, 4th Floor, Civil Engineering Building, Chengdu 610031, China.
School of Civil Engineering, Southwest Jiaotong University, St No. 111, Beiyi Section, Erhuan Road, Chengdu 610031, China.
Materials (Basel). 2021 Jan 18;14(2):452. doi: 10.3390/ma14020452.
The purpose of this research was to investigate and improve the accuracy of the existing slab-track mat (STM) specifications in the evaluation of the vibration reduction effect. The static nonlinearity and dynamic mechanical characteristics of three types of STMs were tested, and then a modified fractional derivative Poynting-Thomson (FDPT) model was used to characterize the preload and frequency dependence. A modified vehicle-floating slab track (FST) coupled dynamic model was established to analyze the actual insertion loss. The insertion loss error evaluated by the frequency-dependent tangent stiffness increased with the increase in STM nonlinearity, and the error obtained by the third preload tangent stiffness was usually greater than that of the second preload. Compared with the secant stiffness, the second preload frequency-dependent tangent stiffness was more suitable for evaluating STMs with high-static-low-dynamics (HSLD) stiffness. In order to reflect the frequency dependence effect and facilitate engineering applications, it is recommended that second preload tangent stiffness corresponding to the natural frequency of the FST be used for evaluation. Furthermore, the insertion loss of the STMs with monotonically increased stiffness decreased as the axle load increased, and the opposite was true for the STMs with monotonically decreased stiffness. The vibration isolation efficiency of the STMs with HSLD stiffness was both stable and better than that of the STMs with monotonic stiffness.
本研究的目的是调查并提高现有板式轨道垫层（STM）规范在评估减振效果方面的准确性。对三种类型的STM的静态非线性和动态力学特性进行了测试，然后使用改进的分数阶导数庞廷 - 汤姆森（FDPT）模型来表征预载和频率依赖性。建立了改进的车辆 - 浮置板式轨道（FST）耦合动力学模型来分析实际插入损失。通过频率相关切线刚度评估的插入损失误差随着STM非线性的增加而增大，并且由第三次预载切线刚度获得的误差通常大于第二次预载的误差。与割线刚度相比，第二次预载频率相关切线刚度更适合评估具有高静态 - 低动态（HSLD）刚度的STM。为了反映频率依赖性效应并便于工程应用，建议使用与FST固有频率对应的第二次预载切线刚度进行评估。此外，刚度单调增加的STM的插入损失随着轴重增加而降低，而刚度单调降低的STM则相反。具有HSLD刚度的STM的隔振效率既稳定又优于具有单调刚度的STM。
