基于调频EMD的结构非线性辨识方法研究  

IDENTIFICATION OF NONLINEAR SYSTEM BY FREQUENCY MODULATED EMD METHOD

作　　者：张欣[1] 杜修力[2] 

机构地区：[1]郑州大学土木工程学院,郑州450001 [2]北京工业大学建筑工程学院,北京100022

出　　处：《工程力学》2011年第8期83-88,共6页Engineering Mechanics

基　　金：城市与工程安全减灾省部共建教育部重点实验室;工程抗震与结构诊治北京市重点实验室开放基金项目(EESR2008-11);河南省重点科技攻关项目(092102310056)

摘　　要：提出了调频EMD方法,克服了原EMD方法在密集频率情况下容易产生固有模式函数(Intrinsic Mode Function,IMF)混淆的弱点,可以较好地分解相对密集频率的弱非线性信号,得到物理意义相对明确的IMF。与Hilbert-Huang变换相结合,有效地识别多自由度弱非线性系统瞬时模态信息的变化过程。通过数值仿真计算证明了调频EMD方法的有效性。利用调频EMD方法对Humber大桥的主梁两自由度节段模型自由气弹振动信号进行识别,揭示了该耦合系统的非线性。Frequency modulated empirical mode decomposition （FM-EMD） method is proposed. The mode mixing problem associated with the original EMD method when processing nonlinear signals with closely spaced frequencies is solved. The physical meaning of the identified intrinsic mode functions （IMFs） is improved. Assisted by the Hilbert-Huang transform, the proposed method can identify the instantaneous parameters of the weak nonlinear system with closely spaced frequencies. The effectiveness of the proposed method is verified by numerical simulations. With the proposed method, nonlinearity is identified in the aeroelastic vibration of the two DOF bridge deck sectional model of Humber Bridge.

关 键 词：非线性 瞬时频率 瞬时阻尼 EMD 调频EMD 

分 类 号：TU311[建筑科学—结构工程] U446[建筑科学—桥梁与隧道工程]