对波数有限元方法进行验证后,结合高速铁路设计规范,建立CRTSⅡ型板式无砟轨道的波数有限元模型,讨论轨道结构各部件弹性模量/刚度变化对轨道结构整体刚度的影响,进行轨道刚度对关键参数的敏感性分析,得到以下主要结论:无砟轨道刚度在低频段和高频段有不同的特征.在低频段(0~第三阶动刚度峰值频率),出现多个共振引起的波谷值和波峰值;在高频段(第三阶动刚度峰值频率~100 Hz),轨道刚度随着频率的增加而减小.轨道各部件中,扣件的刚度对轨道刚度的影响最明显,但其对轨道低频段内的共振频率影响不大;基床底层和地基弹性模量仅影响低频段的轨道刚度,共振频率和轨道静刚度随着弹性模量的增加而增大,最大轨道动刚度的变化不明显;基床表层和CA砂浆弹性模量对轨道刚度的影响较小.%After verification of the wavenumber finite element method ,according to the latest design specifica-tions of high speed railway ,the wavenumber finite element model of the CRTS Ⅱ slab ballastless track was es-tablished .T he influence of the elastic modulus and stiffness variation of each component of the track structure on the overall stiffness of track structure was investigated .The sensitivity of track stiffness to key parameters was analyzed .The main conclusions are as follows :The ballastless track dynamic stiffness has diverse features in the low frequency and high frequency ranges .In the low frequency range (0~the third order peak frequency of dynamic stiffness) ,several crest and valley values appeared .In the high frequency range (the third order peak frequency of dynamic stiffness ~ 100 Hz) ,the track stiffness decreases with the increase of frequency .A-mong all the track components ,the stiffness of the fastener has the most impact on the track global stiffness , but it can hardly affect the resonance frequency in the low frequency range of the track .The elastic modulus of the base course of the subgrade bed and the foundation only affects the track stiffness in the low frequency range .The resonant frequency and the static stiffness of the track increase with the increase of the elastic mod-ulus ,but the change of the maximum dynamic stiffness of the track is minor .The influence of the elastic modu-lus of the subgrade surface layer and CA mortar on the track stiffness is small .
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