使用机械阻抗法在棒材中心实验室测量减振性能

[中文适用范围]： 本 SAE 推荐实践描述了一个实验室测试程序，用于测量由粘合到中心激励振动杆的阻尼材料组成的系统的复合损耗因数和弯曲刚度特性。该棒可以是钢、铝、玻璃或其他金属或复合材料棒，可用于地面车辆、船舶产品和飞机。阻尼材料可以是均质的、非均质的、均质和非均质的组合，在延伸层或约束层配置中与无弹性材料（例如铝箔）一起使用或与无弹性材料（例如铝箔）一起使用。阻尼材料可以是可热粘合材料、背胶片材、可喷涂涂层材料或其他种类的粘弹性材料。这里讨论的阻尼程序提供了测量适用于不同运输系统的频率和温度范围内的阻尼的方法。 [外文原描述]： This SAE Recommended Practice describes a laboratory test procedure for measuring the composite loss factor and bending stiffness properties of a system consisting of a damping material bonded to a vibrating bar which is excited at the center. The bar could be a steel, aluminum, glass, or other metal or composite bar that would be used in ground vehicles, marine products, and aircraft. The damping materials could be homogeneous, nonhomogeneous, a combination of homogeneous and nonhomogeneous, used in conjunction without or with an inelastic material (such as aluminum foil) in an extensional layer or a constrained layer configuration. The damping material could be a heat bondable material, adhesive backed sheet material, sprayable coating material, or other kinds of viscoelastic materials. The damping procedure discussed here provides means to measure damping over a range of frequencies and temperatures found applicable and useable for different transportation systems. The term composite refers to the combination of the vibrating bar and damping material. The composite loss factor is dependent upon the thickness, damping, and modulus of both the vibrating bar and the damping material layer. In many applications the vibrating bar is made of steel. However, in many other applications, the vibrating bar could be different than steel and the frequency range of vibration could also be different. This test methodology does recommend three specific bar sizes based on the vibrating bar material and the general frequency range of interest. However, it also explains and provides the equation that is to be used to size the bar and provides suggestions on the bar size depending on the type of bar material and thickness. This document provides a means of rank ordering damping materials according to their composite loss factor values from test samples that represent typical applications for a given vibrating bar. However, the method can also be used to determine the damping performance of the bar by itself, such as steel, aluminum, glass, composites, etc.