本IR定义了最常见夹具设计的一般分类（分类）。该IR为设计、制造和安装提供了指南，以改进测试重复、再现和与车辆状况相关的方式。本IR中不同类型的夹具（包括其预加载）适用于单端制动惯性测功机NVH测试，频率范围在1.25 kHz和16 kHz之间（根据SAE J2521）。本IR适用于额定车辆总重为4536 kg或以下的乘用车和轻型卡车。本IR不涉及其他可变性来源，例如（a）试验程序本身，（b）环境条件，（c）测功机设计，包括其NVH试验箱，（d）数据收集和数据分析方法，以及（e）制动器和悬架硬件的零件到零件、批次到批次以及设计水平的变化。

This IR defines a general taxonomy (classification) of the most common fixture designs. This IR provides guidelines for design, fabrication, and installation to improve the way tests repeat, reproduce, and correlate to vehicle conditions. The different types of fixtures in this IR (including their preloading) apply to single-ended brake inertia dynamometer NVH testing, with a frequency range between 1.25 kHz and 16 kHz (per SAE J2521). This IR applies to passenger car and light trucks with a gross vehicle weight rating of 4536 kg or below. This IR does not address other sources of variability such as (a) test procedure itself, (b) environmental conditions, (c) dynamometer design, including its NVH test chamber, (d) data collection and data analysis methods, and (e) part-to-part, batch-to-batch, and design-level variation for brake and suspension hardware.