Research On High Frequency Dynamic Stiffness And Creep Characteristics Of Rubber Isolators

Rubber vibration isolators are important vibration isolation components for automobiles.The performance of the rubber isolator is closely related to the NVH performance of the car,and at the same time has a great impact on the handling stability and reliability of the car.The high-frequency dynamic stiffness and creep characteristics of rubber isolators are a weak point in the current product development stage of rubber isolators.Therefore,this paper studies the early development and design of rubber isolator.The main work of the paper is as follows:1)Research on prediction method of high frequency dynamic stiffness of the rubber isolator.The original and cross-point dynamic characteristics of the rubber isolator are analyzed,and the test method of the high-frequency dynamic performance of the rubber isolator is discussed.Based on a series of test results of the rubber isolator and the rubber test piece,a hyper-elastic-generalized Maxwell superposition constitutive model suitable for the calculation of high-frequency dynamic stiffness of rubber isolator is studied.The expression method of superposition constitutive model in finite element software Abaqus is discussed.The parameter identification method of the superposition constitutive model is derived.The high-frequency dynamic stiffness of a rubber isolator is calculated and compared with the test results to verify the effectiveness of the high-frequency dynamic stiffness prediction method for the rubber isolator.The effects of amplitude excitation,preload,diameter reduction and loading method on high-frequency dynamic stiffness are analyzed.2)Research on the prediction method of creep characteristics of the rubber isolator.Based on the shear creep test results of rubber test pieces,the creep properties of rubber materials were verified.The hyper-elastic-nonlinear viscoelastic superposition constitutive model is used to describe the creep characteristics of rubber materials.The expression method of superposition constitutive model in finite element software Abaqus is discussed.The method of identifying the parameters of the constitutive model is studied.The creep characteristics of a rubber isolator are calculated and compared with the test results to verify the effectiveness of the prediction method of creep characteristics of the rubber isolator.Comparing the calculation results of the hyper-elastic-nonlinear viscoelastic superposition constitutive model and the hyper-elastic-generalized Maxwell superposition constitutive model,the results show that the hyper-elastic-nonlinear viscoelastic superposition constitutive model has better prediction effect.3)Research on optimal method of high frequency dynamic stiffness of rubber isolator.In order to improve the high-frequency vibration isolation performance of the rubber isolator,a method of optimizing the high-frequency dynamic stiffness by designing the flap for the rubber isolator is studied.In order to study the influence of various design parameters of rubber flap on high-frequency dynamic stiffness,a rubber isolator was taken as the research object.The installation direction,installation position,angle of the flap,height of the flap,and number of flap were studied respectively.The research results provided guidance and support for the optimal design of the high-frequency dynamic stiffness of the rubber isolator.