Tuning of natural frequency with electromagnetic shunt mass

Abstract

In previous studies, the negative impedance electromagnetic shunt damping (EMSD) can increase the damping of host structures to reduce the unexpected vibration. This paper proposes a novel electromagnetic shunt mass (EMSM) concept, which can tune the natural frequency of an electro-mechanical system and simultaneously suppress vibration. The EMSM means that the mass of a system can be controlled with the EMSD. An electromagnetic transducer is designed and modeled. The negative inductance negative resistance (NINR) and the positive inductance negative resistance (PINR) shunts are proposed to investigate the tuning of the natural frequency characteristics. The governing equation of the coupling system is derived, and the EMSM model is established in frequency domain. The optimal resistance and inductance of the shunt are analyzed theoretically, and the root locus is employed to judge the stability of the coupling system. The laboratory experiment was setup to verify the EMSM concept. The results demonstrate that the EMSM can electrically tune the natural frequency of the electromagnetic transducer. Furthermore, the NINR-EMSM has the excellent performance in isolation region, and the PINR-EMSM is more effective to suppress the low frequency vibrations in resonant region.

Bond-Slip Monitoring of Concrete Structures Using Smart Sensors—A Review

“…Conversely, the geometry of the piezoelectric material will deform according to the applied electrical field [ 31 , 32 , 33 ]. The direct effect of the piezoelectric material can be utilized for sensing [ 34 , 35 ], energy harvesting [ 36 , 37 , 38 , 39 , 40 ], or passive vibration damping [ 41 , 42 , 43 , 44 ], and the converse effect can be used as actuators [ 45 , 46 , 47 , 48 ]. Owing to their unique property of dual sensing and actuating ability, high bandwidth [ 49 ], and low cost, piezoelectric materials are frequently used in the SHM field as transducers.…”

Exact Solutions for a Novel H₂ Optimal Design of Electromagnetic Tuned Mass Damper

“…According to the conclusions of scholars such as Zheng [6] and Inoue [7], the electromechanical coupling coefficient is related to the stiffness of the main system , electromagnetic coefficient and coil inductance ,while the electromagnetic coefficient and coil inductance coefficient are related to the number of turns n, width D and length of the coil. Therefore, the optimization of EMTMD could not consider the parameter electromechanical coupling coefficient, but only consider the optimization of two parameters including tuning ratio and damping ratio.The electromechanical coupling coefficient can be given a reasonable value.…”

“…Thus, the advantage of this two parameters optimization method is that the coil inductance can be set relatively small, so the coil DC resistance will be small, and the connection of analog circuits such as negative inductance and resistance as in Ref. [6] can be avoided, also the complexity of the control system being reduced spontaneously .…”

“…If Ref. [6] were designed according to the optimization of two parameters, the EMTMD can be used for multi-modal vibration control of structures without connecting negative inductance and negative resistance spontaneously.…”

Piezoelectric Shunt Stiffness in Rhombic Piezoelectric Stack Transducer with Hybrid Negative-Impedance Shunts: Theoretical Modeling and Stability Analysis

“…Up to now, few studies considered the stiffness effect of negative-capacitance shunted PSD. Zheng et al [53] discussed the tuning of natural frequency with an electromagnetic shunt mass. Consequently, this study focuses on the stiffness mechanism of PSD, and discusses the use of the negative stiffness to enhance the structural vibration isolation performance.…”