A theoretical vibration‐reduction effect analysis of the floating slab track supported by nonlinear variable stiffness isolators and semi‐active magneto‐rheological dampers
A theoretical vibration‐reduction effect analysis of the floating slab track supported by nonlinear variable stiffness isolators and semi‐active magneto‐rheological dampers
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DOI：
10.1002/stc.2829
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发表时间：
2021-08
影响因子：
5.4
通讯作者：
Ze-ming Zhao;Kai Wei;Fang Cheng;Huailong Li;Ping Wang
中科院分区：
文献类型：
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作者：
Ze-ming Zhao;Kai Wei;Fang Cheng;Huailong Li;Ping Wang
非线性振动控制理论解决了传统线性振动控制理论无法解决的一些瓶颈问题。为改善传统钢弹簧浮置板轨道的低频减振效果，将智能可控磁流变阻尼器（MR‐Ds）和高静低动变刚度隔振器（VS‐维斯）创新性地应用于传统钢弹簧浮置板轨道。为了确定VS‐VI的合理参数组以及与MR‐D配合使用时的参数匹配，首先通过对FST等效单自由度（SDOF）模型的静力和动力分析初步提出了参数组。建立了垂向车辆-变刚度-磁流变FST耦合动力学模型，并基于安全性和减振分析对参数组进行了优化。仿真结果表明，正刚度和负刚度是决定VS-VI刚度非线性水平和动力支承能力的关键参数。提高正刚度是必要的，以实现无车辆载荷下的低动态刚度，并确保FST在车辆载荷下的毫米级动态位移。适当的刚度非线性水平可以达到较好的减振效果，过大的非线性水平不会带来更显著的改善。动力分析中的阻尼比是防止跳变现象的关键参数，推荐值不应小于5%。此外，当VS-VI和MR-D有效结合时，较小的MR阻尼力和较大的位移阈值不仅可以实现更好的减振效果，而且可以降低能耗。
Nonlinear vibration control theory has resolved some bottleneck problems that cannot be solved by traditional linear vibration control theories. In this study, intelligent controllable magneto‐rheological dampers (MR‐Ds) and high‐static‐low‐dynamic variable stiffness vibration isolators (VS‐VIs) are innovatively applied to a traditional steel‐spring floating slab track (FST) to improve its low‐frequency vibration‐reduction effect. To determine the reasonable parameter group of the VS‐VI and the parameter matching when used with MR‐D, parameter groups were first preliminarily proposed through static and dynamic analyses of the equivalent single‐degree‐of‐freedom (SDOF) model of the FST. A vertical vehicle–variable stiffness‐magneto‐rheological FST coupled dynamic model was established, and the parameter group was optimized based on safety and vibration‐reduction analyses. The simulated results showed that the positive and negative stiffnesses were the key parameters that determined the stiffness nonlinearity level and dynamic support capacity of the VS‐VI. Improving the positive stiffness is necessary to achieve a low‐dynamic stiffness under no vehicle load and to ensure the millimeter‐level dynamic displacement of the FST under vehicle load. An appropriate stiffness nonlinearity level can achieve a better vibration‐reduction effect, and excessive nonlinearity level will not bring more significant improvements. The damping ratio in the dynamic analysis is a key parameter to prevent the jumping phenomenon, and the recommended value should not be less than 5%. Moreover, when the VS‐VI and the MR‐D were efficiently incorporated, a smaller MR damping force and larger displacement threshold could not only achieve a better vibration‐reduction effect but also reduce the energy consumption.