基于谐波窗函数的桥梁振动信号分解与重构

Decomposition and reconstruction of bridge vibration signals based on the harmonic window function

针对桥梁损伤检测过程中需要对原始振动信号中各阶次模态信号进行提取的需求,提出了一种利用自定义谐波窗函数进行信号提取方法。阐述了谐波窗函数的构建方法及信号提取时的分解与重构过程。对一钢筋混凝土梁的实测振动信号进行了分解与重构,提取了梁的五阶振动信号。实验结果表明,设计的谐波窗函数可以实现信号频段的自由划分;提取的信号具有无数据量损失、无相移、信号失真小等特点;可在信号提取的同时,实现噪声滤除。

Extraction of various order signals from the original beam vibration response signals is required in bridge damage detection.In this paper,a new method of signal extraction based on custom harmonic window function was proposed.The definition of custom harmonic window function and the process of decomposition and reconstruction were demonstrated.Five order vibration signals were extracted after decomposing and reconstructing the original vibration response signals of reinforced concrete beams.The results indicated that the custom harmonic window function could be used to achieve the free division of the signal frequency band.The extracted signal had no data loss,phase shift,or small signal distortion,and the noise was filtered simultaneously during signal extraction.