体腔填充材料的声学性能的实验室测量

[中文适用范围]： 本 SAE 推荐实践描述了一种实验室测试程序，用于测量由形成矩形横截面通道的体腔填充材料组成的系统的声学性能。用于此测试的材料可能包括热反应和化学反应产品@有或没有架子以模拟应用中的挡板@或体腔填充物和铝箔的组合以增强性能。这些材料通常安装在地面车辆@等运输系统中，从而减少通过轨道@摇杆@和支柱/柱子的噪音传播。本文件旨在对使用通用汽车钢@的通道上应用的材料的声学性能进行排序，以便可以轻松评估除材料之外的夹焊缝密封效果。然而@通道不是车辆的实际部分（即@现实生活中的部分）@因此必须仔细解释本研究获得的结果，考虑到部分尺寸/形状和部分完全密封（或不完全密封）的限制。声学性能以插入损耗 (IL) 表示，如第 3 节测试方法中所述。此处描述的测试程序基于 SAE J1400 中描述的方法。然而，本文件与 SAE J1400 方法的不同之处在于，J1400 测量声音传输损失，而本文件测量空腔中体腔材料的 IL。本文档涵盖了 1/3 倍频程中心频率中感兴趣的有用频率范围。实际频率范围的下限受到通道尺寸和/或混响室体积的限制。本标准引用了两种矩形截面通道。它们的横截面尺寸为 75 mm x 75 mm 和 150 mm x 150 mm，并分别提供 800 Hz 和 400 Hz 1/3 倍频程频率@及以上的有效数据@，前提是混响室可以在这些频率下产生扩散声场。 [外文原描述]： This SAE Recommended Practice describes a laboratory test procedure for measuring the acoustical performance of a system consisting of a body cavity filler material formed into a rectangular cross-section channel. Materials for this test may include both heat reactive and chemically reactive products, with or without a shelf to simulate a baffle in an application, or a combination of body cavity filler and aluminum foil to enhance the performance. These materials are commonly installed in transportation systems such as ground vehicles, and thus reduce the noise propagation through the rails, rockers, and pillar/posts.This document is intended to rank order the acoustical performance of materials for application on channels using general automotive steel, such that the effects of sealing of pinch welds in addition to the material could be easily evaluated. However, the channel is not an actual part (i.e., real life section) of the vehicle, and therefore results obtained from this study will have to be carefully interpreted considering limitations of section size/shape and full sealing (or not) of the section.The acoustical performance is expressed in terms of insertion loss (IL) which is described in Section 3 Test Method. The test procedure described here is based on the method described in SAE J1400. However, this document differs from the SAE J1400 method in that the J1400 measures sound transmission loss, and this document measures IL of body cavity materials in a cavity.This document covers the useful frequency range of interest in 1/3 octave band center frequencies. The lower limit of the actual frequency range is limited by the size of the channel and/or the volume of the reverberation room. Two rectangular cross-section channels are cited in this standard. These are 75 mm × 75 mm and 150 mm × 150 mm in cross-section and provide valid data at and above 800 Hz and 400 Hz 1/3 octave band frequencies, respectively, provided the reverberation room can generate diffuse sound field at those frequencies.Cross Reference: ANSIS1.1,ANSIS1.11,ANSIS1.4,ANSIS1.40,J1400_201707,J184_201408,TSB003