一种基于经验模式分解的结构损伤预警方法

Structural Damage Alarming Based on Empirical Mode Decomposition

提出了一种基于经验模式分解的结构损伤预警方法。首先,将结构反应信号用经验模式分解方法分解成一系列固有模态函数;然后,利用固有模态函数在结构损伤前后的能量分布变化来表征结构因损伤引起的动力特性改变;最后,计算结构的损伤预警指标。应用该方法对健康监测Benchmark模型结构进行分析,采集模型在锤击激励下结构损伤前后的动力响应,计算了结构损伤预警参数及其损伤预警指标。试验数据分析表明,基于经验模式分解的结构损伤预警指标具有良好的损伤预警能力,能够准确地判断结构初期损伤的发生。

A structural damage alarming method is proposed using empirical mode decomposition.The intrinsic mode functions are firstly obtained from the empirical mode decomposition of structural response signal,and then the energy redistribution of the intrinsic mode functions is used to reflect the variation of the structural dynamic characteristics caused by the structural damage,on the basis of which structural damage indices are calculated.This damage diagnosis is employed to analyze Benchmark model structure proposed by the International Association for Structural Control and the American Society of Civil Engineers(IASC-ASCE) Task Group on Structural Health Monitoring.The structural dynamic responses from the hammer-impact tests are collected then the damage alarming parameters and the damage alarming indices are evaluated.The experimental results reveal that the structural damage alarming indices based on empirical mode decomposition is able to effectively detect the structural initial damage with preferable damage alarming capacity.