Dynamic Characteristics Accurate Simulation Study Of Top Mount

Rubber materials are widely used in automobiles.Their dynamic characteristics have a great influence on the smoothness,handling stability and NVH characteristics of automobiles.Therefore,how to establish a high-precision dynamic model for virtual prototyping to obtain the complete dynamic characteristic curve of rubber components and the optimization of viscoelastic material parameters are of great significance in guiding the development of rubber components.This article mainly studies the dynamic characteristics of Top mount.The main research contents are as follows:1)Introduce the viscoelastic constitutive theory of rubber materials.From the basic form of the viscoelastic constitutive model,three typical viscoelastic constitutive equations are studied:complex model,standard rheological model and fractional derivative model.Different types of constitutive equations have different ranges of application and have their own advantages and limitations.The center of research is the fractional derivative constitutive model.2)Study the dynamic properties of rubber materials.Studying the changes in the mechanical properties of rubber materials after considering the viscoelastic properties of the materials,including creep,stress relaxation,frequency dependence,and temperature dependence.Determine the viscoelastic model of the rubber element in the time and frequency domain and calculate the constitutive model parameters.3)Perform finite element analysis on the Top mount dynamics.The finite element model of the Top mount is established completely and static properties and dynamic characteristics of Top mount are studied based on the initial viscoelasticity material parameters.The calculation results show that the relative error between the calculated value and the measured value of the dynamic stiffness is controlled within 15%,which meets the accuracy requirements of the engineering application.The relative error between the calculated value and the measured value of the damping angle is a maximum of 20.2%,which does not meet the accuracy of the engineering application.Requirements,need to optimize the parameters of viscoelastic materials.4)Optimize Top mount viscoelastic material parameters.Using Adaptive Response Surface optimization method to search for the optimal value of rubber viscoelastic parameters,re-establish the viscoelastic model based on time domain,calculate the force-displacement curve of Top mount with constant excitation amplitude and different frequency excitation conditions,and reconstruct the dynamic characteristics of Top mount.The analysis results show that the relative error between the calculated and measured dynamic stiffness decreases from 11.55%to 8.78%.The relative error between the calculated value and measured value of the damping angle decreases from 20.2%to 13.85%,making the dynamic characteristics of Top mount meet the engineering application.Accuracy requirements indicate that the use of an adaptive response surface method to optimize the parameters of rubber viscoelastic materials can effectively reverse the parameters of rubber viscoelastic materials.