Abstract:

For some small size structures required to obtain the damping parameters precisely, damping identification method of half-power bandwidth by the dynamic ping method was often unsatisfactory. Herein, on the basis of confirming the principal formulas of the damping identification, a new test method was proposed to identify damping parameters in the frequency domain by sweep excitation through vibration shaker exciter, which was on the improvement of classic half-power bandwidth method and was named as FBM. Moreover, this new method was subdivided into the following two damping identification methods, i.e. direct response method and response with a reference signal(RSFBM)  in frequency domain. And their test and identification process were illustrated respectively by practical damping measurement which was carried out on the research object of small size and thin cantilever plate. At last,the detailed influences on damping results were discussed and analyzed in the aspects of the sweep rate, sweep direction and the two different identification methods. This study can provide an important reference to experimental damping test in engineering field.

Key words: base excitation, frequency bandwidth method(FBM), thin cantilever plate, damping test

摘要：

对于一些需要精确获得阻尼参数的小尺寸结构件,锤击半功率带宽阻尼识别方法往往难以满足要求。在明确阻尼辨识原理的基础上，对经典的半功率带宽阻尼识别方法进行改进,提出一种采用振动台扫频激励的方式在频域上识别小尺寸构件阻尼参数的新方法，命名为频域带宽法。将该方法细分为直接频域响应法和有参考信号频域响应法，对小尺寸悬臂薄板进行了实验研究。比较了扫频速率、两种阻尼辨识方法、扫频方向对阻尼参数的影响，进一步验证了频域带宽法的有效性。

关键词: 基础激励, 频域带宽法, 悬臂薄板, 阻尼测试