Car body sound vibration roughness NVH design method based on low frequency acoustic sensitiveness inside vehicle

Abstract

The invention relates to a method for designing the automobile body acoustic vibration unevenness NVH based on a low frequency automobile acoustic sensitivity. The method comprises the following steps: firstly, establishing a body-in-white finite element modeling, and establishing an acoustic finite element modeling for a cab on the basis of the body finite element modeling; secondly, carrying the frequency response analysis on the positions of a suspending point of an engine on the automobile body, a suspension mounting point, an exhaust hanging point, and the like; thirdly, taking the vibration speed of a body wall plate obtained by the frequency response analysis as a boundary condition, and the sound pressure level beside ears of a driver by solving the acoustic response of the cab; further, the influence level of larger sheet metal parts and mounting points which have great influence on the sound pressure level are acquired by checking the vibration situation of the body wall plate displayed by the frequency response analysis result at higher sound pressure response frequency points, and analyzing the sheet metal contribution; and finally, amending the design proposal of the sheet metal parts and the design proposal of the local rigidity of the mounting points.

Description

technical field [0001] The invention relates to a method for predicting the noise level inside a vehicle, in particular to a method for designing NVH of the vehicle body acoustic vibration roughness based on low-frequency vehicle interior acoustic sensitivity. Background technique [0002] The passenger compartment of a car is a typical elastic thin-wall cavity structure, and its inner wall is composed of frame structures such as columns and beams and thin plate structures such as floor and ceiling. Under the excitation of the powertrain and chassis components, the overall structural vibration generated by the frame structure such as columns and beams, the local vibration of the thin plate structure of the vehicle body, and the vibration of the cavity air in the vehicle interact with each other to produce coupling effects, resulting in annoying low-frequency booming noise. [0003] Acoustic sensitivity analysis, also known as sound pressure transfer function analysis, refer...

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This analysis has a mature theory in the field of academic research, but its application in engineering practice remains to be studied

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