Abstract: In order to reduce the lowfrequency structural noise in the cab, a finite element model and a coupled acoustic boundary element model of the cab structure of a tractor were established, and the harmonic response of the structure was analyzed. Taking the structural displacement results as the boundary conditions of sound field analysis, the coupled frequency response of sound field and sound vibration in the cab was analyzed based on the indirect boundary element method. The plate contribution method was used to calculate and analyze the plate that contributes significantly to the main peak frequency of the drivers ear sound pressure, and the vibration was suppressed. For the ceiling with a large contribution to the analysis results, the morphology was optimized, and the right window and right door were thickened. The results show that the sound pressure level of the interior noise in the frequency range of 20-200 Hz has been significantly improved, and the overall noise level has decreased by 3.01 dB (A), which effectively improves the acoustic environment in the cab, and provides a case basis for the lownoise design in the cab of the same kind.

Key words: tractors, cab, low frequency noise, coupled acoustic boundary element, harmonic response, plate contribution

摘要： 为降低驾驶室内低频结构噪声，建立某拖拉机驾驶室结构有限元模型和耦合声学边界元模型，对结构进行谐响应分析，并以结构位移结果作为声场分析边界条件，基于间接边界元法对驾驶室内进行声场声振耦合频率响应分析；应用板件贡献量法计算分析得到对驾驶员耳旁声压主要峰值频率处贡献显著的板件，并进行振动抑制；对分析结果中贡献量较大的顶棚，进行形貌优化处理，对右窗和右门进行加厚处理。结果表明，车内噪声在频率20~200 Hz范围内的声压级水平得到比较明显的改善，整体噪声水平下降3.01 dB(A)，有效改善驾驶室内声学环境，为同类驾驶室内低噪声设计提供案例依据。

关键词: 拖拉机, 驾驶室, 低频噪声, 耦合声学边界元, 谐响应, 板件贡献量