In order to study the vibration reduction effect of rubber pads under cement or asphalt layers of viaducts, the vertical dynamic model of vehicle-track-bridge coupling is established based on dynamic compliance method. Only 1/8 of the wheel-pair system of the vehicle and the primary suspension are considered. The rails are regarded as infinitely long Timoshenko beams and the bridge is simplified as a simply supported Euler beam. The fastener system, cement or asphalt layer and the rubber pads are simplified as a linear spring-damping system. The wheel-rail contact force is calculated in frequency domain using the wheel dynamic compliance, rail dynamic compliance and linear contact compliance. This contact force is then applied to the rail to calculate the dynamic responses of the rail, track sleeper panels and the bridge. The vibration reduction effect of the rubber pads is evaluated by the vibration acceleration level, the acceleration level insertion loss and the Z-level insertion loss. The results show that the vibration response of the rail is slightly increased after the rubber pads are installed and the insertion loss of the Z-level is-0.81 dB;the vibration response of the track sleeper panel increases significantly and the Z-level insertion loss is-10.3 dB;the vibration response of the bridge decreases obviously and the Z-level insertion loss is 15.6 dB. The calculation results show that the rubber pads can effectively reduce the vibration response of the bridge structure. The relevant research provides a reference for vibration and noise reduction of bridges.%为探讨下橡胶垫对桥梁减振效果,基于动柔度法建立车辆-轨道-桥梁耦合的垂向动力学模型,车辆考虑1/8轮对系统,只考虑一系弹簧阻尼计算车轮动柔度,钢轨看作无限长Timoshenko梁,桥梁简化为简支的Euler梁,扣件系统、橡胶垫用线性弹簧阻尼单元模拟,联合车轮动柔度、钢轨动柔度和线性接触动柔度计算频域轮轨力并施加到钢轨上,计算钢轨、道床板、桥梁的动力响应.采用振动加速度级、加速度级插入损失和Z振级插入损失评价橡胶垫的减振效果,结果表明,采用橡胶垫后钢轨振动响应略有增大,Z振级插入损失为-0.81 dB,道床板振动响应大幅增加,Z振级插入损失为-10.3 dB,桥梁的振动响应减小明显,Z振级插入损失为:15.6 dB,计算结果表明橡胶垫能有效的降低桥梁结构振动,相关的研究为桥梁的减振降噪提供了一定参考.
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