Operation mode damping identification method, damage detection method, system and equipment

Abstract

The invention discloses an operation mode damping identification method, a damage detection method, a system and equipment, and the method comprises the steps: collecting a time domain response signal of a to-be-detected structure in a random sub-sample form, obtaining a plurality of groups of random sub-sample signals, calculating a cross-correlation function of each group of random sub-sample signals through a natural excitation technology, obtaining a free vibration signal, and carrying out the detection of the free vibration signal. And a sparse coefficient matrix of each free vibration signal is calculated by using an orthogonal matching pursuit algorithm, and a modal damping ratio is determined according to the sparse coefficient matrix, so that the operation modal damping of the to-be-detected structure is identified and obtained. According to the operation modal damping identification method disclosed by the embodiment of the invention, a random sub-sample signal acquisition method is adopted, the requirements of a natural excitation technology are met, modal damping identification under working excitation is realized, an identification framework adopted in the embodiment is frequency-vibration mode-damping, the identification precision is improved, and the identification efficiency is improved. And technical support is provided for accurate identification of structural damage. 本发明公开了一种运行模态阻尼识别方法、损伤检测方法、系统及设备，通过以随机子样本形式采集待检测结构的时域响应信号，得到多组随机子样本信号，利用自然激励技术计算各组随机子样本信号的互相关函数，得到自由振动信号，利用正交匹配追踪算法计算得到各个自由振动信号的稀疏系数矩阵，根据所述稀疏系数矩阵确定出模态阻尼比，从而识别得到所述待检测结构的运行模态阻尼。本实施例公开的运行模态阻尼识别方法，采用随机子样本信号采集的方法，满足了自然激励技术的要求，实现对工作激励下的模态阻尼识别，并且本实施例中采用的识别框架为频率‑振型‑阻尼，提高了识别精度，为结构损伤的精确识别提供了技术支持。