Study Of Staddle Monorail Train-track Beam Coupling System Dynamics

Based on train-bridge coupling dynamics theory and the Chongqing monorail transportation dynamic performance test, the straddle monorail train-track beam coupling system dynamics and track beam design parameters are studied, and the main research contents and conclusions are as follows:(1)A three-dimensional monorail transportation train model and bridge model are established.The governing equations of motion for monorail train are derived using Lagrange’s formulation,and the stiffness matrix and damping matrix of the train are obtained; a monorail bridge model is established using finite element software.(2)Track irregularity are simulated. Based on trigonometric series, track irregularity of railway, road and monorail are simulated.during calculation and analysis, track irregularity of the steering wheels and stabilizing wheels are simulated using power spectrum density of Japanese steel track beam irregularity, walking wheels using United States six analog spectrum.(3)A dynamic response analysis procedure for train-bridge is proposed.Based on the dynamics theory of monorail train-bridge interaction and Newmark-β method, this paper proposes an analytical procedure for traffic-induced vibration of a monorail train-bridge coupling system using MATLAB. Analytical results on dynamic response of the monorail train and bridge are compared with field-test data in order to verify the validity and reliability of the proposed analysis procedure, and a positive correlation is found.(4)The frequency limits and dynamic coefficient of track beam are researched. Displacement dynamic coefficient at the center of span are obtained under different speed, using static analysis and dynamic analysis,and the relationship between dynamic coefficient and frequency is discussed,the linear fitting formula about dynamic coefficient and frequency is detemined, according to the least squares method.(5)Beam high seting 1.6m is more reasonable, when the span of simply supported beam exceeds 22 and vehicle speed exceeds 30km/h, both the vehicle and the track beam have a good dynamic performance.(6)A simply supported beam of 22m is designed and checked, which the results show that Prestressing steel sets very reasonable.The results of this paper can be applied to similar engineering calculation, and provide a reference for further improvement of straddle monorail design and standards.