Development of a Semi-Active Electromagnetic Vibration Absorber and Its Experimental Study

Abstract

In this work, a semiactive electromagnetic vibration absorber has been developed based on a proposed electromagnetic stiffness adjustable spring model, which presents a new solution for adjusting stiffness in the field of vibration absorber devices. Simulation study on the electromagnetic spring has been performed to determine the structural parameter of the semiactive vibration absorber. An experimental rig is also built up to investigate its practical vibration control effectiveness. Firstly, the finite element model of the test bench is used to analyze its vibration characteristics. Then, the vibration reduction effect is predicted through the simulation analysis, from which the optimal control positions are found. Finally, the experimental studies are also conducted, and the results show that this semiactive electromagnetic vibration absorber has a frequency adjustment range from 21 Hz to 25 Hz, in which considerable vibration reduction from 5 dB to 10 dB can be achieved.

A New Approach to Achieve Variable Negative Stiffness by Using an Electromagnetic Asymmetric Tooth Structure

“…The idea of electromagnetic asymmetric tooth structure comes from the design of the traditional electromagnetic tooth structure (TETS), also called electromagnetic spring, which has been used in vibration absorption [22]. The axisymmetric schematic diagram of the TETS is shown in Figure 1 cell are made by electrical iron that has high permeability.…”

“…The magnetic flux of the upper close stator tooth becomes larger and that of the lower close stator tooth is contrary; thus, the direction of the overall electromagnetic force is also upward, same as the moving direction of the active cell, and the system is unstable. When the active cell moves upwards 3.5 mm above the equilibrium position, it is interesting that the magnetic field of the EATS is similar to that of the traditional tooth structure with positive stiffness characteristic and detailed analysis can be found in [22]. Table 2 shows the parameters used in analytical calculation of the electromagnetic force.…”

Design of natural frequency adjustable electromagnetic actuator and active vibration control test

“…The performance of NFAEA depends mostly on the output electromagnetic force and the magnetic induced intensity of coil. In an effort to optimize the thickness of yoke, NFAEA is electrified by a current of 1 A and the thickness of yoke varies from 1 mm to 15 mm (referring to the design experience of actuator in Liu et al 14 ) while holding all other experimental variables constant. It can be seen in Figure 6 that electromagnetic force and magnetic induced intensity increase before 11 mm, then remain stable between 11 mm and 13 mm, and decrease after 13 mm.…”

Magnetorheological Elastomer Stiffness Control for Tunable Vibration Isolator

“…Various methods and materials have been proposed to reduce vibration. The methods are broadly classified as a passive, semi-active, or active system [1][2][3][4][5].…”