Identification for joint interfaces with correlation analysis of instantaneous dynamics
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Dynamic responses of the assembled structures are mainly dependent on the contact state of the joint interfaces. The identification method by combining the empirical mode decomposition (EMD) with the correlation analysis is used to identify the contact preload of the joint interfaces. The EMD is used to decompose the recorded dynamic responses into a series of intrinsic mode functions (IMFs). The instantaneous dynamics are then extracted to investigate the frictional effects of the joint interfaces, and the similarity characteristic with correlation analysis of the IMFs is also constructed to identify the contact preload. Experimental investigations of the typical lap-type bolted joint beam and monolithic beam subjected to impact excitation are performed to verify the proposed dynamics analysis method. Four IMFs are chosen to investigate the frictional effects of joint interfaces by a comparison with direct time-/frequency-domain analysis and experimental modal analysis, which are also used to construct the correlation matrix to identify the contact preload. The results show that the frictional effects of the bolted joint interfaces have a great impact on the dynamic responses of the bolted joint beam, inducing the softening stiffness and additional joint damping characteristics, especially for the higher frequency modes. The correlation value of IMFs can be used to identify the contact preload of the bolted joint interfaces effectively.
KeywordsJoint interfaces Contact identification Empirical mode decomposition Instantaneous dynamics Correlation analysis
The work is supported by the Science Challenge Project (Grant No. TZ2018007). The authors also thank the National Natural Science Foundation of China (Grant No. 11872059) for providing the financial support for this project.
- 3.Segalman, D.J., Gregory, D.L., Starr, M.J., et al.: Handbook on Dynamics of Jointed Structures. Sandia Report (2009-4164). Sandia National Laboratories, Albuquerque (2009)Google Scholar
- 10.Smallwood, D.O., Gregory, D.L., Coleman, R.G.: Damping Investigations of a Simplified Frictional Shear Joint. Sandia Report (2000-1929). Sandia National Laboratories, Albuquerque (2000)Google Scholar
- 12.Demarie, G.V., Ceravolo, R., Sabia, D., et al.: Experimental identification of beams with localized nonlinearities. J. Vib. Control 14(11), 903–995 (2011)Google Scholar