【摘要】 浮轨式扣件是一种高等减振扣件，在我国地铁线路服役后出现钢轨短波长波磨，导致显著的车内振动噪声。为探明浮轨式扣件轨道动力特性，利用有限元软件ABAQUS建立浮轨式扣件轨道结构三维实体有限元模型，采用模态分析和谐响应分析研究柔性轮对作用下的轨道动力特征。结果表明：周期性离散支撑轨道的简化截断边界引起的高频振动波反射效应对轨道动力特性影响明显，浮轨式扣件轨道模型长度涵盖大于80个承轨台间距后可忽略边界波反射的影响；轨道结构在80 Hz以下主要表现为钢轨和道床板整体的弯曲和扭转振动，大于80 Hz的轨道振动表现为钢轨相对道床板的弯曲和道床板自身的弯曲及扭转振动；轨道垂向动力特性在500 Hz以内受单个轮对作用的接触刚度和质量效应影响显著，而在钢轨一阶垂向pinned-pinned共振频率之后受柔性轮对与接触刚度的耦合作用影响甚微；考虑双轮对加载后，转向架双轮对间钢轨会出现局部弯曲振动特征；轨道垂向动力特性在车轮一阶弯曲、车轮二阶弯曲和车轮伞向模态影响下出现谐波峰值。更多还原

【Abstract】 A floating fastener is a type of resilient fasteners with very low vertical stiffness. However, short-pitch rail corrugation occurs on tracks with the floating fasteners on China metro lines, resulting in large vehicle interior vibration noise. To investigate the dynamic characteristics of the track, a three-dimensional finite element model of the track was established using the finite element software ABAQUS. Modal analysis and harmonic response analysis were conducted to investigate the dynamic characteristics of the track loaded by flexible wheelsets. Results show that: the wave reflection effect caused by the simplified truncated boundary of a periodically discrete supported track on the dynamic characteristics of the track is significant when the length of track in the numerical model is not enough. The effect of the boundary wave reflections can be ignored when the length of track model in the frequencies of below 1 500 Hz is more than 80 sleeper spacings. In the frequencies of 10-80 Hz, the vibration modes of the track structure are bending and torsional vibrations of rail and slab as a whole. However, at above 80 Hz, the rail vibrates relative to the slab which also shows a bending vibration. The vertical dynamic characteristics of track at below 500 Hz are significantly influenced by the wheel-rail contact stiffness and the wheelset mass. However, they are not influenced by the contact stiffness and the wheelset mass when the frequency is large than the first-order vertical pinned-pinned resonance frequency of the rail. The rail will show local bending vibration characteristics if double wheelsets of the bogie are considered. Harmonic peaks appear of the vertical dynamic characteristics of track under the influence of the first-order bending, second-order bending, and umbrella modes of the wheel.更多还原