摘要
运行状态模态分析可在自然激励条件下识别结构真实的动力学特性。基于半功率谱估计进行模态参数识别是其中一类重要方法,但实际应用在效率、稳定性等方面存在不足。本文利用因果信号的Hilbert变换理论,推导了H谱变换函数的估计方法,并结合多参考点最小二乘复频域法实现运行状态模态参数识别。采用含有近频模态的7自由度仿真算例和悬臂梁实测算例对该算法进行了可靠性验证,并与传统的半功率谱函数法进行了比较。结果表明,H谱变换函数具有计算速度快、极点更稳定等优点,更适用于实际工程应用。
The dynamic characteristics of structure can be identified by Operational Modal Analysis （OMA） under natural excitation conditions. The Positive Power Spectral Density （PPSD） method is one of the most important methods for modal parameter identification but lack of security and efficiency in a practical application. This paper presents a new function describing the dynamic behavior, which can be obtained by applying Hilbert transformation to the power spectrum function of the output response. The principle of modal parameters identification based on the poly-reference least square complex frequency domain method（PolyMAX） is also introduced. The presented meth- od is validated by a simulation example of 7 degrees of freedom. Compared with the method based on the half power spectral density function, the new method has clearer frequency stability chart. Finally, the method is successfully applied to a practical modal test of a cantilever beam.
出处
《地震工程与工程振动》
CSCD
北大核心
2014年第6期97-102,共6页
Earthquake Engineering and Engineering Dynamics
基金
中央高校基本科研业务费(NS2013004)
江苏高校优势学科建设工程资助项目
关键词
运行模态分析
参数识别
HILBERT变换
半功率谱
operational modal analysis
parameter identification
Hilbert transform
half power spectrum
