Nonstationary Random Vibration Performance of Train-Bridge Coupling System with Vertical Track Irregularity

In order to study the random vibration performance of trains running on continuous beam bridge with vertical track irregularity, a time-domain framework of random analysis on train-bridge coupling system is established. The vertical rail irregularity is regarded as a random process. A multibody mass-spring-damper model is employed to represent a moving railway car and the bridge system is simulated by finite elements. By introducing the pseudo excitation algorithm into the train-bridge interaction dynamic system, expressions of the mean value, standard deviation, and power spectral density of the nonstationary random dynamic responses of bridge and vehicles are derived. Monte-Carlo simulations are implemented to validate the presented method. A comprehensive analysis of the train-bridge coupling system with vertical track irregularity is conducted focusing on the effect of the randomness of the vertical rail irregularity on the dynamic behavior of the running train and the three-span continuous concrete bridge. Moreover, stochastic characteristics of the indicator for assessing the safety and the riding quality of the railway cars running on continuous beam bridge are carried out, which may be a useful reference in the dynamic design of the bridge.

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Singular Function Models of a Simply Continuous Beam Bridge under a Moving Load

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.2240 ◽

2012 ◽

Vol 204-208 ◽

pp. 2240-2243

Author(s):

Jun Zhang ◽

Ming Kang Gou ◽

Chuan Liang ◽

Xiao Lu Ni ◽

Zi Wen Zhou

Keyword(s):

Present Model ◽

Dynamic Models ◽

Moving Load ◽

Dynamic Responses ◽

Singular Function ◽

Moving Mass ◽

Continuous Beam ◽

Concentrated Force ◽

Continuous Beam Bridge ◽

Beam Bridge

The system of a simply continuous beam was looked on as one span beam with several internal elastic supports of inexhaustible stiffness. There were two types of models such as the dynamic models by a moving concentrated force and by a moving mass. A three-span beam was introduced as example solved with the present model by a moving concentrated force and FEM, which verified that the present model was correct. Two cases of the example bridge by a moving concentrated force and by a moving mass were considered. The results indicate that mass of the moving load has little influence over the dynamic responses of the simply continuous beam bridge.

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Non-Stationary Random Vibration Analysis of Railway Bridges Under Moving Heavy-Haul Trains

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455418500359 ◽

2018 ◽

Vol 18 (03) ◽

pp. 1850035 ◽

Cited By ~ 10

Author(s):

Zhihui Zhu ◽

Lidong Wang ◽

Zhiwu Yu ◽

Wei Gong ◽

Yu Bai

Keyword(s):

Random Vibration ◽

Vertical Acceleration ◽

Railway Bridges ◽

Coupling System ◽

Ballasted Track ◽

Heavy Haul ◽

Train Speed ◽

Track Irregularity ◽

Heavy Haul Trains ◽

Track Bridge

This paper presents a non-stationary random vibration analysis of railway bridges under moving heavy-haul trains by the pseudo-excitation method (PEM) considering the train-track-bridge coupling dynamics. The train and the ballasted track-bridge are modeled by the multibody dynamics and finite element (FE) method, respectively. Based on the linearized wheel-rail interaction model, the equations of motion of the train-ballasted track-bridge coupling system are then derived. Meanwhile, the excitations between the rails and wheels caused by the random track irregularity are transformed into a series of deterministic pseudo-harmonic excitation vectors by the PEM. Then, the random vibration responses of the coupling system are obtained using a step-by-step integration method and the maximum responses are estimated using the 3[Formula: see text] rule for the Gaussian stochastic process. The proposed method is validated by the field measurement data collected from a simply-supported girder bridge (SSB) for heavy-haul trains in China. Finally, the effects of train speed, grade of track irregularity, and train type on the random dynamic behavior of six girder bridges for heavy-haul railways are investigated. The results show that the vertical acceleration and dynamic amplification factor (DAF) of the midspan of the SSB girders are influenced significantly by the train speed and track irregularity. With the increase in the vehicle axle-load, the vertical deflection-to-span ratio ([Formula: see text]) of the girders increases approximately linearly, but the DAF and vertical acceleration fail to show clear trend.

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