Study On The Stiffness And Vibration Characteristics Of Automobile Hub Bolt Connection

The threaded connection is widely used in the automobile structure,and the hub bolt connection is the main way of the automobile hub connection,which plays an extremely important role in the performance and safety of the vehicle.The dynamic characteristics of hub bolt connection are important factors that affect the ride comfort,safety performance and comfort performance of vehicle.In this paper,load characteristics,connection stiffness and vibration characteristics of bolt connection of automobile hub are studied systematically from the axial and transverse aspects.The structure of the bolt connection of the automobile hub is analyzed.According to the balance condition of the force and the condition of the deformation coordination,the axial and lateral load characteristics of the bolt connection of the automobile hub are studied,and the change of the radial force between the hub and the supporting surface are obtained.The interactions between each component of hub bolt connection is analyzed,and the dynamic axial and transverse system model is established.Based on the Newton's law,the dynamic differential equation is established,and the dynamic response is solved with linear superposition and the four order five level Runge-Kutta algorithm.Finally,the variation of the axial and lateral displacement is calculated.Besides,the change of stress of wheel bolt is analyzed with the dynamic displacement response of hub.An equivalent axial and lateral stiffness model is established according to the force acting on the connection of the hub bolts.Based on the fractal theory and Hertz contact theory,the stiffness of each component of the automobile hub bolt connection and the contact stiffness between the joints are analyzed and calculated.The influence of the load on the hub bolt connection on the axial stiffness and lateral stiffness is obtained by combining the stress analysis of the single hub bolt connection.Based on the interaction of the interaction force between the components of a car hub bolt,a dynamic model of the translation and torsion coupling is established.Based on the second law of Newton,the differential equation of the system dynamics is derived.By using the expansion of Fourier series,the natural frequency of the derived system corresponding to the nonlinear system is calculated,and the dynamic response of the system is obtained by numerical method.The assembly model of automobile hub bolt connection was established by SolidWorks 3D software,and the modal simulation was carried out by Ansys workbench,and the six natural frequencies and vibration modes before the wheel bolt connection were obtained.