Technology Research And Test Passenger Car Compartment Acoustics Modes

With the remarkable improvement of people’s living standards, people’s comfort andsafety requirements are more stringent automobile ride. Vehicle noise is not only an importantindicator of the evaluation of the comfort noise generated by the car has become a part of ourlives noise. Passenger car interior noise on ride comfort also cause impacts, it may not onlyaffect the normal communication between people, especially in the high-decibel noise for along time driver in the driver will easily cause earache, fatigue and thus a security risk. Modalanalysis of acoustic test chamber in the automotive vehicle is a very important part of thestudy of NVH, identifying the entire passenger compartment modal system for the passengercompartment noise, avoid cavity resonance has a very important significance. Passenger roomwith a chair, three-dimensional space of the interior, larger, complex structure, its modalanalysis has been more difficult.This article is based on the theoretical basis of modal analysis, modal test way to acompact SUV domestic cars for the study, the use of modal testing methods acquire the modalparameters of acoustic tests. Compared with the results calculated modal analysis and verifythe correctness of the results each other, and the acoustic modal test analysis were studied indetail.At first this paper describes the basic methods and theories relevant steps of modal test,followed by the establishment of acoustic modal test system of vehicle compartment inaccordance with an experimental basis, using professional acquisition and analysisinstrumentation synergy data logger for data processing and analysis, Then identify the modalfrequencies through MATLAB, access to car experimental modal parameters chamber tune,method of least squares fitting with the natural frequency of the amplitude of each measuringpoint when then come to the car compartment tune the natural frequencies correspondingmode shapes. And then compare the calculation of modal parameters, and its error analysis,analysis of the passenger compartment to provide experimental basis for noise reduction.