基于S变换的结构损伤信号处理

针对结构损伤信号的非平稳特性，推导了离散S变换及其基本实现算法，并验证其在信号处理中的有效性，探讨了S变换与傅里叶变换的数值关系；基于S变换分析了一单跨两层钢结构试验模型的节点损伤信号的时频特性，提取各损伤信号的每时能量最大值作为特性指标，对不同节点损伤程度的信号进行了对比。结果表明:当节点损伤程度加剧时，结构损伤信号的能量最大值的极值先减小后增大；当节点损伤程度超过50%时，损伤信号的能量最大值的极值高于节点健康状态的极值。

Structural Damage Signal Processing Based on S-transform

Aimed at the non-stationary of structural damage signal, the basic algorithm of discrete S-transform was deduced and S-transform was verified to have the feature of validity in signal processing. The numerical relationship between S-transform and Fourier transform was discussed. Based on S-transform, the time-frequency characteristics of a single span two-story steel framed structure with joint damage were analyzed. The signal identification index of maximum energy value per moment was extracted and comparisons of different joint damage extents were made. The results indicate that the extreme of maximum energy value per moment of the structure decreases first and then increases when the joint damage extent intensifies, and it is higher than the extreme of health status when the joint damage extent is over 50%.