Magnetorheological Fluid with Nano Fe₃O₄ for Performance Enhancement of MR Damper for Seismic Resistance of Steel Structures

Abstract

Magnetorheological damper (MR damper) is one of the promising vibration control systems, applicable for damping seismic induced vibrations in structures, because of their ability to be controlled and to adapt their mechanical properties by varying the magnetic field, their high damping force, their low energy input required and their simple use. This paper presents the experimental results carried out to study the use of Nano Fe3O4as component of MR fluid. The Nano Fe3O4particles are obtained by an indigenous process to convert a waste product of chemical industry. The performance of Nano Fe3O4MR fluid is compared with five commercially available samples in the market namely, Mill scale, cast iron (1), cast iron (2), carbonyl iron and white iron oxide. Surface morphology was identified using SEM & the average particle size was analysed using XRD. Viscosity & settling measurements were also performed for all the six samples. Shake table tests were conducted to study the performance of steel frame with MR damper. The model for the study was a single bay three storey steel frame where the response of the structure, in terms of acceleration, velocity and displacement was observed. It was observed that the percentage of reduction in displacement, velocity, acceleration, approximately 40 – 67% for structure with MR damper.

Analytical Approach of a Pure Flow Mode Serpentine Path Rotary Magnetorheological Damper

“…A smaller gap would give the flow more friction loss that can lead to a higher pressure drop. Moreover, Equations (19) and (20) show that the magnetic flux would increase if the reluctances of each material can be minimized. So, if the width of the gap is designed to be smaller, it would lead to a higher magnetic field.…”

“…The value of magnetic reluctance is affected by the distance that the flux passes through, the surface area covered by the flux, and the magnetic permeability of each material. The reluctances of each material can be obtained by Equation (20). R = L/µA (20) The analytical method used a linearized approach in magnetic flux calculation.…”

“…The reluctances of each material can be obtained by Equation (20). R = L/µA (20) The analytical method used a linearized approach in magnetic flux calculation. It often provides serious error in prediction, as stated by Yu et al [21].…”

“…Rotary MR dampers move on the rotation direction and their output is damping torque. Linear MR dampers have already been applied as vehicle shock absorbers [18], prosthetic knee [19], and civil application [20], but the application of linear MR dampers on braking systems is difficult [21]. Moreover, linear MR dampers have some limitations, such as huge installation space [22] and restriction of stroke because of the risk of buckling of the damper rod [23].…”

A Review on the Magnetorheological Fluid, Damper and Its Applications for Seismic Mitigation

“…Braz Cesar commented on MR damper tested in a metallic frame of 3 story with 3 -DOF to control the vibration and the dynamic properties of MR Damper is tested as depicted in Figure 32 and 33. The numerical investigation using clipped optimal algorithm the system identification and dynamic behaviour of a structure system is simulated [64][65].…”