NVH Performance Analysis And Structural Optimization Of A Light Truck Interior Body

With the increasing requirements of consumers for vehicle ride comfort,optimizing and improving the NVH performance of the vehicle and its components has become the primary problem to be solved in vehicle research and manufacturing.In order to improve the NVH quality of the whole vehicle,the performance analysis and structural optimization of the NVH of a light truck interior body were carried out by means of simulation modal analysis,dynamic stiffness analysis,noise transfer function and experimental modal analysis.The main research contents are as follows:1)Modal analysis of the interior body: Hypermesh software was used to establish the finite element model of the interior body and conduct modal analysis of the structural performance of the interior body.Of interior body white body,steering systems,seat,instrument panel,door,three pedals,both inside and outside rearview mirror seven system components such as modal analysis respectively,the analysis results compared with the target,does not meet the requirements of the system components were optimized respectively,compared to the original state of natural frequency values increased 12.5 Hz and 2.96 Hz,respectively,conform to the requirements of the enterprise.2)Answer the dotted dynamic stiffness analysis: double stents left before the installation of interior body point,the front to stand right front point,left point,right point control arm,control arm suspension left after installation points and suspended right after install six key dotted into action stiffness analysis,calculated by dotted in dynamic characteristics under the condition of the external excitation,calculate the average dynamic stiffness values of each point,compared with the target to judge each point average dynamic stiffness values conform to the requirements.3)Noise transfer function analysis of the acousto-solid coupling system:establish the sound cavity model of the cab of the interior decoration body.Firstly,conduct modal analysis of the sound cavity model and analyze whether the model is accurate according to the previous several modes.After analyzing the noise transferfunction of the acoustic cavity model of the interior body,the calculation results were compared with the target value,and it was found that the maximum z-direction pressure level of the left and right support points of the torsion bar was 66.9d B and68.4d B,respectively,which were both higher than the target value of 65 d B and did not meet the requirements.After optimization and improvement by adding linerboard and floor stiffener,the maximum z-direction pressure level of the left and right support points of the optimized torsion bar is 64 d B and 64.5db respectively.All the results of the final calculation of the noise transfer function are in line with the requirements.4)Modal test analysis of interior trim body: using the LMS test.lab The white body experiment modal analysis system,white body each order modal vibration mode and frequency,each order modal simulation comparing with the results and the experimental modal,the error between the two are less than 2%,modal vibration mode,also can prove that the cab white body simulation modal analysis results are accurate.Through the analysis and optimization of the interior decoration body,the NVH performance of the vehicle is significantly improved.The research results provide a certain reference value for the vibration and noise control of similar vehicles.