关键词: 模态分析, 阻尼比, 最大熵谱, 定阶

Abstract:

In this paper, the method of determining damping ratio by comparing MEM spectrum is discussed and the shortcoming of this method is pointed out. Then a new method for determining damping ratio is proposed. The theory and algorithm of this method arc introduced. The results of simulation and practical computation of vibration signals show that the proposed method is efficient and accurate. In this paper the order choosing of autoregressive model is also discussed. A new criterion based on AIC is put forward, in which the influence of signal noise is considered.practical applications show that the criterion is applicable to various SNR situationr.

Key words: Model analysis: Damping ratio, MEM spectrum, Order choosing