New insights into coherence analysis with a view towards extracting structural natural frequencies under operational conditions》.pdfVIP

Measurement 77 (2016) 187–202 Contents lists available at ScienceDirect Measurement journal homepage: /locate/measurement New insights into coherence analysis with a view towards extracting structural natural frequencies under operational conditions Wang-Ji Yan a, Zhouquan Feng b,⇑, Wei-Xin Ren a a Department of Civil Engineering, Hefei University of Technology, Hefei, Anhui 230009, People’s Republic of China b Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong a r t i c l e i n f o a b s t r a c t Article history: Coherence function as a fundamental measure of the degree of relationship between two Received 20 March 2015 time series has numerous applications in diversified fields such as financial economics, Received in revised form 9 August 2015 stochastic simulation and signal processing. In this study, the magnitude-squared coher- Accepted 19 August 2015 ence function which enables one to identify frequency-domain correlation between two Available online 7 September 2015 time series is revisited with a view towards extracting natural frequencies directly for dynamic structural systems. This study makes a successful attempt at mathematically Keywords: proving that coherence function in the modal domain converges to unit while coherence Coherence analysis