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为了提高结构损伤识别的精度和计算效率,提出了一种基于结构振动信号的统计特征的损伤识别方法。该方法直接从测试信号中提取时域特征信息,而无需将信号变换到频域中。与频域方法相比,既简化了复杂的运算过程,又降低了测量噪声对识别结果的干扰。在推导了白噪声激励下结构各测点位移响应间的统计特性(相关系数)的基础上,证明了振动信号统计特征中包含了结构的模态信息,进而为使用结构振动信号的统计特征作为损伤识别指标提供了依据。理论分析结果还表明结构响应信号的统计特征有很好的抗噪性。最后以某一连续梁桥为例进行了数值仿真模拟,计算结果表明,白噪声激励下结构位移响应间回归系数的变化能很好的反应结构损伤位置和程度。
In order to improve the accuracy and computational efficiency of structural damage identification, a damage identification method based on the statistical characteristics of structural vibration signals is proposed. The method extracts time-domain feature information directly from the test signal without the need to transform the signal into the frequency domain. Compared with the frequency domain method, it not only simplifies the complicated operation process but also reduces the interference of the measurement noise to the recognition result. On the basis of deducing the statistical characteristics (correlation coefficient) between the displacement responses of each measuring point under the excitation of white noise, it is proved that the statistical characteristics of the vibration signal contain the modal information of the structure, and as a result of using the statistical characteristics of the structural vibration signal as Damage identification indicators provide the basis. The theoretical analysis also shows that the statistical characteristics of the structure response signal have good noise immunity. Finally, a numerical simulation is carried out with a continuous beam bridge as an example. The calculation results show that the change of regression coefficients between structure displacement responses can reflect the location and extent of structural damage well under white noise excitation.