Open AccessIdentification of modal parameters in a lightly damped system based on impact vibration testing: Application of exponential window and removal of its effect
Author(s) -
Daiki Tajiri,
Masami Matsubara,
Shozo Kawamura
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1264/1/012011
Subject(s) - modal , frequency response , exponential function , vibration , modal testing , noise (video) , control theory (sociology) , modal analysis , window function , system identification , mathematics , acoustics , computer science , engineering , mathematical analysis , statistics , spectral density , physics , image (mathematics) , control (management) , database , artificial intelligence , polymer chemistry , electrical engineering , measure (data warehouse) , chemistry
The experimental environments for impact tests are simple to construct compared to other vibration tests in experimental modal analysis. However, given that sufficient sampling time is necessary for the response to attenuate, the following two problems arise: The first is that work efficiency is lowered. The second is that the measurement time increases, which makes it more susceptible to noise. To solve these problems, it is common to shorten the sampling time and apply an exponential window to reduce the leakage error of the frequency response function (FRF). Although studies on the influence on the FRF exist, identification accuracy for damping characteristic and the influence on the residue have not discussed. In this study, the influence on the modal properties obtained and the accuracy of the results are clarified using numerical examples based on a circle fit and method using simultaneous equations of the real and imaginary parts of the FRF. Finally, the identification results were compared and made sure that the method using simultaneous equations of the real and imaginary parts of FRF can identify modal properties with high accuracy. This method is effective for improving the working efficiency and reducing the influence of noise.