Vibration suppression of a viscoelastic isolation system by nonlinear integral resonant controller

Abstract

The nonlinear integral resonant controller (NIRC) is implemented and analyzed to control the vibration of a viscoelastic isolation system under harmonic excitation. The NIRC consists of a first-order resonant integrator, which provides additional damping in the closed-loop system to reduce the high-amplitude vibration near the resonance frequency. The method of multiple scales is applied to analytically find the relationship of the amplitude–frequency response of the viscoelastic isolation system. Besides, the equation of the backbone curve satisfied is derived. Meanwhile, the suppression performance is verified based on time-domain analysis. It is found that the NIRC can effectively suppress vibration and improve stability of the viscoelastic isolation system. Furthermore, the influence of the detuning parameters, the real-power exponent, the viscoelastic damping, and the external excitation amplitude on the stability regions is investigated. Overall, the vibration reduction mechanism of the NIRC on the viscoelastic isolation system is revealed.

Increasing the damping of oscillatory systems with an arbitrary number of time varying frequencies using fractional-order collocated feedback

“…[15] ), flatness (e.g. [16] ) based feedback laws have been developed, as well as the integral resonant control (a recent nonlinear version of this is [17] ). These techniques guarantee robust stability but do not achieve phase margin robustness, i.e, approximate damping robustness of all the vibration modes.…”

Nonlinear mode decomposition-based methodology for modal parameters identification of civil structures using ambient vibrations

“…Modal parameters (MPs) such as natural frequencies and damping ratios have a great significance in distinct fields of civil engineering because they allow characterizing and identifying different properties of civil structures, which can be used for vibration control [1][2][3][4], structural health monitoring [5][6][7], energy harvesters [8] and updating of analytical models [9][10][11]. Therefore, the accurate identification of MPs through ambient vibrations (operational modal analysis, OMA) and artificial vibrations (experimental modal analysis, EMA) is of paramount interest [12][13][14][15].…”