稳态简谐激振,在频域中对应单一谱线,激振能量集中在单一频率,属单频激振。其优点是激振功率大,因而信噪比高,能保证低响应机械阻抗数据的测试精度。只要扫描足够慢或频翠步长足够小,可以得到很高分辨率。缺点是试验周期很长(对小阻尼试件,取得一组机械阻抗数据往往费时数十分钟);如采用模拟式阻抗分析仪,动态范围和精度受到限制。七十年代以来,采用各种宽频激振的测试技术引起很大重视。随机测试以白噪声发生器 Steady-state harmonic excitation, in the frequency domain corresponding to a single spectral line, the excitation energy concentrated in a single frequency, is a single frequency excitation. The advantage is the excitation power, and therefore high signal to noise ratio, to ensure low response mechanical impedance data test accuracy. As long as the scan is slow enough or Frequent steps small enough, you can get very high resolution. The disadvantage is that the test period is very long (for a small damping specimen, it takes tens of minutes to obtain a set of mechanical impedance data); if using an analog impedance analyzer, the dynamic range and accuracy are limited. Since the seventies, using a variety of broadband excitation test technology has attracted great attention. Randomly tested with a white noise generator