CRTSⅡ型板式无砟轨道-桥梁耦合模型中的钢轨与底座板频响特性研究

针对高速铁路常用的CRTSⅡ型板式无砟轨道结构,根据其特点,建立二维模型时,可将钢轨与底座板模拟为无限长Euler-Bernoulli梁。根据动力学基本原理,首先建立无限长Euler-Bernoulli梁在简谐荷载作用下的运动微分方程,通过稳态响应求解和积分变换,求出梁体的位移、速度和加速度频率响应函数。利用所推导的频响函数,探讨CHN 60型钢轨的位移、速度和加速度频率响应的频谱特性和频响衰减率。通过分析可知,钢轨的位移和速度频率响应随频率增加而降低,而加速度频率响应随频率增加而增大;位移频响衰减率随频率增加而显著降低,速度频响衰减率在10~100 Hz频段较大,加速度频响衰减率随频率增加而显著增大。

Research on Frequency-Response Characteristics of Rail and Base Plate in CRTSⅡ Ballastless Slab Track-Bridge Coupling Model

For CRTS typeⅡballastless slab track commonly used on high-speed railway,the rail and base plate can be modeled as Euler-Bernoulli beam of infinite length when a 2D model established based on the characteristics of the track.Firstly,according to the basic principle of dynamics,the motion differential equation of an infinite Euler-Bernoulli beam excited by a harmonic load is established.With steady-state solution and integral transformation,the frequency response functions of displacement,velocity and acceleration are obtained.The spectrum characteristics and attenuations of the displacement,velocity and acceleration frequency responses of CHN 60 rail are explored with deduced frequency response functions.The results show that the displacement and velocity frequency responses of the rail decrease with the increase of frequency,however,the acceleration frequency response expands with the increase of frequency.Moreover,frequency response attenuation of the displacement decreases obviously with the increase of frequency.The frequency response attenuation of the velocity achieves its maximum in 10~100 Hz and that of the acceleration expands with the increase of frequency.