基于频域快速数值算法的浮置板轨道隔振性能

Vibration isolation performance of floating slab track based on fast numerical algorithm in frequency domain

以移动谐振荷载下浮置板轨道的力传递率为评价依据,研究浮置板轨道的隔振性能.视浮置板轨道为周期性无限轨道结构,在移动谐振荷载作用下,运用周期结构响应性质,建立浮置板轨道的频域快速数值算法.运用该算法计算浮置板轨道力传递率,进而对浮置板轨道的隔振性能进行分析.研究表明:对于某一激振频率的移动荷载,浮置板轨道力传递率较大的频段就位于荷载自身频率附近,且力传递率的主要峰值个数由轨道的频散特性决定;浮置板轨道不同位置的隔振性能不同,尤其当荷载频率在低频段时,浮置板端部的隔振性能最差,越往中部隔振性能越好;随着荷载速度的增加,荷载频率附近频段的力传递率会有所下降,但其他大部分频段的力传递率会有所升高.

The force transmission rate of floating slab track（FST） under harmonic moving load is used as the evaluation basis to research the vibration isolation performance of FST. FST is regarded as a periodic-infinite track structure, under the harmonic moving load, through using the characteristic of pe- riodic structure＇s dynamic response, a fast numerical algorithm in frequency domain of FST is established. Then the force transmission rate is calculated through this algorithm and the vibration ilation performance of FST is researched. Researches show that contrary to a moving load with a certain excitation frequency, the frequency band where the force transmission rate of FST is significant is near the load frequency, and the main peak number of the force transmission rate is determined by the dispersion characteristics of track. The vibration isolation performances at different locations of FST are different, especially when the load frequency is at low-frequency band, the vibration isolation performance is worst at the end of a slab, but it gradually become better as the location moving towards the middle of a slab. With the increase of load speed, the force transmission rate in the frequency band around the load frequency will decrease but in most other frequency band will increase.