A Rapid Calculation of the Vibration of the Bridge with Constrained Layer Damping Based on the Wave and Finite Element Method

As an important part of rail transit, the vibration and noise of bridges have been a hot issue in recent years. The vibration and noise problem of steel-concrete composite bridges is more serious than that of concrete bridges. The vibration characteristics of steel-concrete composite bridges with and without constrained layer damping are studied based on the wave and finite element method and superposition principle. Firstly, based on the wave finite element method, a calculation model of the vibration response of a steel-concrete composite bridge is established, and the calculation results using this method agree well with those obtained by the traditional FEM and the field measurement. The dominant frequency band of the bridge vibration is 63-100 Hz and 500-1000 Hz, and the peak appears at 80 Hz. Secondly, the segment model of the bridge with constrained layer damping is established. The dynamic equation is constructed using the stiffness and mass matrix from the model to solve its response under the wheel-rail force. The constrained layer damping can reduce the vibration acceleration level of steel components by 5-10 dB. The influence of material and thickness of constraining layer on the vibration reduction is analyzed.