Systematic design of a magneto-rheological fluid embedded pneumatic vibration isolator subject to practical constraints

Abstract

A systematic design of a magneto-rheological fluid embedded pneumatic vibration isolator (MrEPI) considering practical constraints and optimal performance is proposed. The design procedure basically consists of three steps, i.e. system level design, component level design and practical realization. The system level design involves synthesizing appropriate non-dimensional system parameters of pneumatic spring and MR damper elements based on parameter sensitivity analysis considering requirements for compact and efficient hardware utilization. The component level design involves optimal design of the MR valve by minimizing an objective function in terms of non-dimensional geometric, material and excitation parameters, and guaranteeing required performance in the worst cases. Then practical realization involves determining actual plant parameters from the non-dimensional analysis in system and component level designs with the considerations of practical requirements/constraints. To verify the effectiveness of this optimization procedure, the semi-active vibration control performance of the optimized MrEPI subject to harmonic disturbances is evaluated, which shows good isolation performance in all tested cases. This study actually provides a systematic method for the optimal analysis and design of all those nonlinear vibration isolators consisting of pneumatic spring and MR damper elements. This is achieved firstly by developing effective sensitivity analysis of dominant design parameters upon the adjustable stiffness and damping capacity irrespective of bulky or small system mass configuration and subsequently via a systematic realization design with the consideration of practical constraints in applications.

Optimal design of control valves in magnetorheological fluid dampers using a nondimensional analytical method

“…In order to evaluate the effectiveness of the optimally designed MR control valve in vibration isolation system, the semiactive control performances of an MR fluid-embedded pneumatic vibration isolator (MrEPI) using the optimally designed MR valves are investigated. The MrEPI is a generic nonlinear vibration isolator consisted of pneumatic springs and MR dampers with hybrid compact connection allowing independently adjustable stiffness, damping, and height control with large maneuverable range (Zhu et al, 2011(Zhu et al, , 2012. For the MrEPI, its stiffness could be first adjusted at an appropriate value according to the application requirements through the regulation of additional pressure ratio f P01 or additional volume ratio f V 01 by pneumatic on-off valves and then the active damping under such a stiffness is only controlled via the MR control valve with appropriate controllers in order to achieve vibration suppression over a broad frequency band (Zhu et al, 2012).…”

A new magnetorheological mount featured by changeable damping gaps using a moved-plate valve structure

“…The optimal design and high damping force engine mount based on both annular and radial flow paths were analyzed and presented in [13]. An isolator embedded pneumatic with using MR fluid was studied in [14] which could provide a systematic method for the optimal analysis.…”

“…From the above literature survey on the MR mount consisting of valve structure, it is clearly understood that the shear mode and flow mode of MR fluid are always a main choice in mount design. Recently, the piston-type structure presented in [1,4,5,7,14] is widely used in the design of MR structures because of its simplicity and easy maintenance. However, in an application of an MR structure with a high damping force, the disadvantage of the pistontype requires large dimensions radially and in height of structure because of the increased area for both the magnetic field and power of the electric coil.…”

Flow Mode Magnetorheological Dampers with an Eccentric Gap

“…Also, the response time is fast (a few milliseconds), and the required power consumption is low (tens of watts). As a result, MR dampers have been employed as vibration mitigation devices for a number of applications, such as seismic dampers [1][2][3][4][5][6][7], seat dampers [8][9][10][11], and vibration isolators [12][13][14][15][16]. More recently, MR dampers have been also applied to aerial and ground vehicles as crashworthiness devices, such as landing gear oleos [17][18][19][20], impact dampers [21][22][23][24][25][26], and energy absorbers [27][28][29].…”