Abstract: In order to achieve the goal of sound pressure level beside the ear of a cab, a liquid applied sound damping (LASD) is applied to the interior of its cab for noise control. Through modal analysis, the preliminary coated area is identified using the modal integrated strain energy method. Noise transfer function (NTF) and panel contribution analysis is performed on the cab (uncoated project) to identify the sheet metal with higher response to noise and form the optimized coating project. Comparing the three project of the uncoated project, the coated area before and after optimization, it is found that the sound pressure level of the optimized project is reduced by 2.7 dB in the X direction excitation -25 Hz, the sound pressure level is reduced by 2 dB in the Y direction excitation -66 Hz, the sound pressure level of the optimized project is reduced by 1.2 dB in the Z direction excitation -23 Hz compared with the uncoated project, and the difference in the sound pressure level before and after optimization is relatively small. It shows that the application of LASD can significantly reduce noise of the cab.

Key words: LASD; cab; modal analysis; panel contribution; NTF

摘要： 为实现某驾驶室耳旁声压级目标，在其驾驶室内部应用水性阻尼涂料（LASD）以实现 噪声控制。通过模态分析，利用模态综合应变能法识别出初版喷涂区域，对驾驶室（未喷涂 方案）进行了噪声传递函数（NTF）和面板贡献量分析，识别出对噪声响应较高的钣金，并 形成优化后喷涂方案。对比未喷涂方案、喷涂区域优化前、优化后三种方案，发现优化后方 案在 X 向激励-25 Hz 的声压级较未喷涂方案降低了 2.7 dB，Y 向激励-66 Hz 的声压级降低了 2 dB，Z 向激励-23 Hz 的声压级降低了 1.2 dB，优化前后声压级差异较小。说明 LASD 的应 用可显著降低驾驶室噪声。

关键词: LASD；驾驶室；模态分析；面板贡献量；NTF