Passenger Car Body Vibration Acoustic Comfort Analysis And Optimization Research

As people gradually improve the performance requirements of automotive products, car ride comfort has become an important factor to measure its market competitiveness. While the car interior noise level of the car as an important basis for a measure of comfort is good or bad, so sound and vibration comfort of the body structure of research for interior noise control of major significance.Thesis of passenger car for the study, its interior noise control for the purpose, combined with real car rotating hub test and transfer function test, using the finite element,boundary element numerical analysis methods such as body structure-acoustic coupling system modal analysis and interior noise response analysis, a response to the application of interior noise peak body panels acoustic contribution analysis to determine the contribution of interior noise peak maximum structural panels, finally, an example of simply supported rectangular plate, acoustic radiation characteristics of sheet metal parts to study the impact factor, based on research results, combined with modal analysis and acoustic contribution analysis, propose appropriate measures to improve the body panel to achieve effective control of vehicle noise. The main contents are as follows:First, based on a three-dimensional geometric model of passenger vehicle, establishment its finite element model of BIW, conducted a BIW structural modal finite element analysis and by comparison with the white body modal test results verify the accuracy of the finite element model established, then, based on the finite element model of BIW, adding front and rear doors and back doors, the establishment of a finite element model of a closed body, and closed body structure modal finite element calculation and analysis. According to closed body finite element model establish interior cavity acoustic finite element model, and acoustic model finite element calculation and analysis. Finally, the establishment of a body structure-interior cavity acoustic coupled system finite element, and body structure-interior cavity acoustic coupling model finite element calculation and analysis.According to real car rotating hub test data and transfer function test data, using Transfer Path Analysis (TPA) method, in LMS/TPA modules calculate the engine and drivetrain motivate each body connection point excitation force. Then, in LMS Virtual.lab the each body connection point excitation force is loaded into the body structure-interior cavity acoustic coupling model, calculation interior noise response of engine and drivetrain excitation. by comparing the test results with the real car, verify the accuracy of established body structure-interior cavity acoustic coupling model, reach interior noise prediction purposes.A response to the noise at the back of the left ear crew peaks body acoustic contribution analysis, determine the contribution of the largest car-peak noise structural panels, provide reference for improving the follow-up structure. then, an example of simply supported rectangular plate, acoustic radiation characteristics of sheet metal parts to study the impact factor, based on research results, combined with modal analysis and body panels acoustic contribution analysis, propose appropriate measures to improve the body panels, vibration and noise reduction achieved good results.