Analysis And Research Of Squeak And Rattle CAE In Automotive Instrument Panel Based On Trimmed Body

Squeak and Rattle(S&R),as one of the important components of NVH performance development,is a kind of abnormal noise of high frequency caused by low frequency vibration.More than 80% of the S&R problems are caused by the knock(rattle)or friction(squeak)between the interior accessories.The instrument panel is one of the most important interior systems of vehicles,and its S&R problems are also one of the important sources of abnormal noise in the interior system.Because the instrument panel is close to the driver’s position,the driver has a more direct and clear experience of the S&R generated by the instrument panel.The S&R easily cause the customer to be bored with the driving environment,and even make the customer doubt the quality of the vehicle.Therefore,it is very important and urgent to analyze and research the S&R of automotive instrument panel.Based on the mechanism of S&R and various factors causing it,this paper makes a comprehensive analysis and research on the S&R of instrument panel.Taking an electric SUV instrument panel of an enterprise project as an example,from 3D modeling to finite element modeling,combined with the related S&R tests to development CAE analysis of the instrument panel based on TB state.The buckle stiffness tester is used to test the dynamic stiffness of the automotive IP(Instrument Panel)parts using buckles,and the measured stiffness value is input into the IP finite element model to reflect the true connection state.With the help of the project,the real vehicle spectrum is collected and the response signal of excitation points under different road conditions is obtained.Through the Ziegler SSP-04 Material Compatibility Test Machine,the compatibility of adjacent components of instrument panel subsystem is studied.The risk index of S&R and the corresponding pulse rate of stick-slip motion due to friction are tested and matched.The risk boundary of S&R of instrument panel are screened.Through the indirect S&R CAE analysis method,research the modal array,frequency,strain energy of the instrument panel,the static stiffness of the instrument panel,and the vibration sensitivity of the instrument panel installed in the TB.The structural optimization is carried out according to the set target value and analysis result of the instrument panel;By the direct S&R CAE analysis method,the risk boundary which is easy to generate frictional and knocking noise is identified,and the E-Line modeling method for solving the relative displacement of the risk boundary is used to analyze the transient response of the instrument panel.By analyzing the relative mode contribution of the risk boundary E-Line,the modes with large contributions are searched,and the S&R of the instrument panel is optimized according to the mode,and the strategy of effectively preventing and controlling the S&R of the instrument panel is proposed.Through analyzing and researching the instrument panel of the real vehicle of this project,a more effective S&R CAE analysis method for the instrument panel is obtained.