拖拉机驾驶室内部声场和整车系统耦振的研究

STUDY ON THE COUPLED VIBRATIONS OF THE WHOLE TRACTOR SYSTEM AND ACOUSTIC FIELD INSIDE CAB

本文针对拖拉机的结构特点把它划分为车体、驾驶室板壁结构和内部声场三个子结构,利用声学有限元法和声固耦合的模态综合技术,建立了描述拖拉机整车振动和驾驶室内部噪声响应的统一的数学模型,并把它用于长春-40拖拉机驾驶室内部噪声的响应分析。结果表明,该模型以较少的模态自由度较为真实地描述了整车声固耦合系统,计算结果和试验结果吻合较好。该模型为拖拉机驾驶室的声学设计和减振降噪提供了方法和途径。

In this paper, according to the structural features of a tractor; it is divid edinto three substructures consisting of tractor body, the structural wall panels of cab and interior acoustic field. A unitized mathematic model describing the whole tractor vibrations and interior noise responses is built up by means of the acoustic finite element method and coupled structural-acoustic modal synthesis technique. The use is made of this model to analyze noise responses in Changchun-40 tractor cab. Results indicate that the model can more lifelikely describe the coupled structural-acoustic system of the whole tractor by using a few modal degrees of freedom. The good agreement is shown by comparing the predict edsound pressure levels with measured ones. The model is available to improve the acoustic design cab, and reduce vibrations and structure-brone noises oftractors.