Forecasting method for vehicle body structure-acoustic coupling based on smoothed finite element boundary element method

Abstract

The invention provides a forecasting method for vehicle body structure-acoustic coupling based on a smoothed finite element boundary element method. The method comprises the following steps: generating a vehicle body structure-acoustic grid model; utilizing the smoothed finite element method to perform smooth processing on the stress field in a shell unit; adopting a mixed integral method to perform separate integral of shearing items subjected to shearing strain in the shell under a natural coordinate system; building a smooth Galerkin weak form of a vehicle body shell structure kinetic equation, and obtaining a dynamic equation after the weak form is subjected to discrete processing; creating an acoustic realistic model by using the boundary element method; according to the continuous displacement and pressure of the coupling interface, obtaining a structure-acoustic coupled smoothed finite element boundary element model; performing simulation forecasting by utilizing the coupled model. When the method is used for solving the vehicle body structure-acoustic coupling problem, relatively good calculation effect can be obtained, and the band frequency width can be analyzed more effectively. Moreover, the method has relatively low quality requirements on the model to reduce the pretreatment time, and has a wide engineering application prospect.

Description

technical field [0001] The invention relates to a vehicle body structure-acoustic field coupling prediction method, in particular to a vehicle body structure-sound field coupling prediction method based on a smooth finite element-boundary element method. Background technique [0002] At present, the structure-acoustic field coupling prediction analysis of the vehicle body is an important work in the CAE (computer aided engineering) analysis of the NVH (Noise, Vibration, Harshness, noise, vibration and harshness) performance of the vehicle body. Performance prediction and guidance of NVH performance development are of great significance. [0003] At present, there are analytical methods and numerical methods for vehicle body structure-acoustic field coupling prediction methods, of which analytical methods are generally only for simple problems and models; numerical methods are currently the mainstream prediction methods, including coupled finite element methods and finite ele...

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Problems solved by technology

However, there are also some problems with this type of method. Regardless of the coupled finite element method and finite element / boundary element method, the structural domain analysis in the structure-acoustic field coupling analysis uses the finite element method, because the finite element method model is too "rigid". , there is a numerical dispersion effect, which causes the prediction results to be greatly affected by the model grid size and the calculation frequency

[0004] In order to meet the reliability of the prediction results of the NVH problem of the car body, engineers need to check the quality of the model during the modeling process, which requires a lot of pre-processing time and manpower. Therefore, it is necessary to propose some new prediction methods to improve the prediction result

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