Nonstationary Response of Bridge due to Eccentrically Moving Vehicles at Variable Velocity

摘要

The non-stationary response of a simply supported girder bridge induced by the vehicle travelling at variable speed has been studied. The deck unevenness has been considered as the realization of homogeneous random process described by power spectral density (PSD) function. The vehicle has been idealized as rigid beam connected by front and rear suspension elements moving at an eccentricity with the centre line. The bridge has been idealized as a continuous system with distributed mass, stiffness and damping properties having flexural and torsional degrees of freedom. Monte Carlo simulation technique has been used to simulate deck profile for generation of input samples in numerical integration of the system equations. A detailed parametric study has been conducted to examine the effect of variable speed, suspension characteristics, vehicle mass, eccentricity of vehicle path, torsional rigidity of the bridge and deck unevenness on the dynamic amplification factors of the response.