【作者】 孙安东； 彭斌； 陶焕； 张玉梅；

【Author】 SUN An-dong;PENG Bin;TAO Huan;ZHANG Yu-mei;School of Environment and Architecture,University of Shanghai for Science and Technology;

【机构】 上海理工大学环境与建筑学院；

【摘要】 频率和振型是两项判断既有砌体结构损伤和评定其安全性的重要指标,为了探讨卡尔曼方法的有效性和实际工程应用效果,使用该方法滤波后识别信号。首先通过构造不同信噪比的人工带噪信号,使用峰值点法和卡尔曼方法识别其前两阶频率作对比分析。然后通过环境激励下的动力测试获得墙体在两种状态下7个测点的加速度响应信号,使用卡尔曼方法滤波处理信号后进行前两阶固有频率的识别,通过构造不同测点与参考测点间的传递函数,识别振型分量后再用三次样条函数拟合出对应的前两阶振型。结果表明:卡尔曼方法受先验误差的影响程度较大,与峰值拾取法相比识别频率时的临界信噪比更小,对砖砌体承重墙的频率和振型识别结果符合一般自然规律,能够揭示墙体损伤的发展趋势。更多还原

【Abstract】 The frequencies and mode shapes are two important indicators to judge the damage of existing masonry structure and evaluate its safety. To explore the effectiveness of the Kalman method and the effect of practical engineering applications, the signal after filtering is identified by using this method. Firstly, the Peak Picking method and Kalman method are used to identify the first and second order frequencies for comparative analysis. Then, the acceleration response signals of the seven measuring points in the two states of the wall are obtained through the dynamic test under environmental excitation. After using the Kalman method to filter the signals, the first and second natural frequencies are identified. By constructing the transfer function between different measuring points and the reference measuring points, the vibration mode components are identified. Then using the cubic spline function to fit the first and second vibration modes. The results show that the Kalman method is greatly influenced by the priori errors, and the critical signal-to-noise ratio is smaller when compared with the peak-picking method. In this way, the frequencies and vibration modes identification results of the masonry bearing wall follow the general natural rules. It can reveal the development trend of wall damage.更多还原