CRTS Ⅲ型板式无砟轨道桥梁区段动力学分析

Dynamics Analyses of Elevated Railway Structures of Box Bridges and CRTS Ⅲ Slab Tracks

通过建立CRTS Ⅲ型板式无砟轨道-高架箱梁桥有限元模型,以德国低干扰谱激励下的轮轨垂向力为输入,对CRTS Ⅲ型板式无砟轨道桥梁区段的高架线路动力学响应进行研究。研究结果表明:板壳单元很好地体现高架箱梁桥低频时的整体和局部振动情况,高架箱梁桥自振时顶板变化最为复杂,翼板在20阶以后振动加剧;德国低干扰谱激励下的高架箱梁桥的振动主要集中在200 Hz以下,与其他轨道型式类似;CRTS Ⅲ型板式无砟轨道结构可明显降低高架箱梁桥结构在0-50 Hz频段内的低频振动,是一种具有良好减振作用的轨道结构型式。

A dynamic finite element model of CRTS III slab track and elevated box bridge coupling structure was established. With the vertical wheel/rail forces excited by German low interference spectrum as the input, the dynamic responses of the elevated railway structures of the box bridge and the CRTS III slab track were studied. It is concluded that the plate and shell elements can well reflect the global and local vibration of the box bridge in low frequency range. In the case of free vibration of the box bridge, the variation of the vibration situation of its top plate are the most complex, and the vibration of the overhanging plate is intensified after the 20 th order modal. The vibration of the box bridge excited by the Germany low interference spectrum is mainly concentrated in the frequency range below 200 Hz, which is similar to that of the other type tracks. The CRTS III slab track structure can obviously reduce the vibration of the box bridge structure in 0~50 Hz range. It has a good vibration reduction function.