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用静电耦合法进行内耗测量在国内外获得了广泛的应用。由于它所施加微弱的应力只产生微小的应变,这对于许多材料的测量是非常重要的。由于背景损耗低,能测出微小的内耗变化,并且能在高温场中测量。因此,静电法越来越被人们所瞩目。静电激励是很简单的,只要在一个稳定的直流电压上迭加一个所需频率的交流电压即可。按其配置方式又可分为并激和串激两种(图1)。由图可知,并激法对信号发生器输出阻抗并没有什么要求,而串激法信号发生器则必须是直流低阻抗输出,并且对地
Electrostatic coupling method for internal friction measurement at home and abroad have been widely used. Because of the weak stresses that it exerts, it produces only small strains, which is important for the measurement of many materials. Due to the low background loss, small changes in internal friction can be measured and can be measured in high temperature fields. Therefore, the electrostatic method is more and more people’s attention. Electrostatic excitation is very simple, as long as the superimposed on a stable DC voltage AC voltage of the desired frequency can be. According to its configuration can be divided into and excitement and series two (Figure 1). As can be seen from the figure, and the excitement of the signal generator output impedance and no requirements, while the string method signal generator must be low-impedance DC output, and ground