| The medium-low speed maglev vehicle has the advantages of low noise,small wear,quick start and stop,strong climbing ability and small turning radius,etc.Therefore,it has become an important approach to solve the urban rail transit problems.At present,the three kinds of commonly used F-type expansion rail joints are found that its have poor stiffness at the connection point and the large collision and vibration phenomenon when the vehicle passes through the joints,which leads to the collision between the coil on the suspension rack of the vehicle and the electromagnetic induction plate on the rail,and at the same time causes the vibration problem of the vehicle.In this context,this thesis takes the F-type expansion rail joint of medium-low speed maglev vehicle as the object to study its static stiffness and dynamic problems.The work includes establishing the parametric finite element analysis models and two dynamic models,analyzing the factors affecting stiffness and dynamic properties,deducing the formulas of pressure and surface force distribution in rolling contact area,analyzing contact fatigue of hydraulic support wheel-F-type expansion rail joint.The main content is as follows:(1)The dynamic models of hydraulic support wheel-F-type expansion rail joints and Ftype expansion rail joints-Suspension frame-hydraulic support wheels have been established according to the interaction force between F-type rail joint connector and hydraulic support wheel and based on the nonlinear spring damping model of lankarani-nikravesh and the loads analysis of F-type rail joint connector key parts.The dynamic models include the contact collision and the flexible deformation of parts based on the mode superposition method.The interaction between hydraulic hupporting wheels has been analysed by using dynamic models of F-type expansion rail joints-Suspension frame-hydraulic support wheels.(2)The parametric finite element models of F-type expansion rail joints and suspension frames have been established.The factors of affecting the static strength and stiffness of the F-type expansion rail joints structure have been analyzed,including the geometric shape and size of the structure,as well as the connection mode of the rail joint,and obtain the laws of different factors affecting the strength and stiffness.The modal information of F-type expansion rail joints and suspension frames has also been analyzed.(3)The dynamic properties of expansion rail joint have been studied by using the established dynamic model and simulation model.This thesis analyzes the interaction between the motion states of multiple hydraulic support wheels of a single suspension frame when passing through the F-type expansion rail joint and mainly analyzes the contact collision caused by hydraulic support wheel passing through the gap of F-type expansion rail joint,the laws of structure and material factors affecting contact collision response,and the multiple factors comprehensively affecting contact collision by using orthogonal experiment method.(4)Carter rolling contact theory is used to analyze the distribution law of pressure and tangential force in the contact area when the hydraulic support wheel makes rolling contact on the plane of the flange plate of the F-type expansion rail joint,and the change of pressure and tangential force when the hydraulic support wheel moves on the joint frange plate.And the rolling contact fatigue of contact surface under pulsating circulation force and F-type expansion rail joint part under impact load is analyzed.In this thesis,through the static analysis of the F-type expansion rail joint,the laws of structural factors affecting the stiffness of the joint structure have been obtained.Through the dynamic analysis,including contact collision analysis and rolling contact analysis,the mechanical response of the hydraulic support wheel through the F-type expansion rail joint has been obtained.The conclusions are useful to the design structure of F-type expansion rail joint. |
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