An improved identification method is proposed for the modal parameter identification of multi-modal vibration attenuation signals based on the analytical mode decomposition and the particle swarm optimization. Through examples of analog signals, it is proved that the proposed method can identify modal parameters under a strong colored noise environment. Field tests were carried out on four in-service aluminum alloy reticulated structures to obtain the acceleration response of the structures. The improved identification method proposed in this paper is used to identify the modal parameters of each acceleration response curve, based on which the damping characteristics of the aluminum alloy reticulated structures are analyzed. The results show that the damping characteristics of such structures obey a three-stage change rule, with the increase of the acceleration amplitude. In addition, a practical calculation method of the damping ratios of aluminum alloy reticulated structures is proposed on the basis of the experimental results.

提出了一种基于解析模态分解和粒子群算法的多模态振动衰减信号模态参数识别的改进方法。通过模拟信号实例，证明了该方法可以在强色噪声环境下识别模态参数。在使用中的四个铝合金网状结构上进行了现场测试，以获得结构的加速度响应。本文提出的改进识别方法用于识别各加速度响应曲线的模态参数，在此基础上分析铝合金网状结构的阻尼特性。结果表明，这种结构的阻尼特性服从三阶段变化规律，随着加速度振幅的增加。此外，根据实验结果，提出了一种实用的铝合金网状结构阻尼比计算方法。