Dynamic characteristics of squeeze-type mount using magnetorheological fluid

Author(s):  
Y K Ahn ◽  
J-Y Ha ◽  
Y-H Kim ◽  
B-S Yang ◽  
M Ahmadian ◽  
...  

This paper presents an analytical and experimental analysis of the characteristics of a squeeze-type magnetorheological (MR) mount which can be used for various vibration isolation areas. The concept of the squeeze-type mount and details of the design of a squeeze-type MR mount are discussed. These are followed by a detailed description of the test set-up for evaluating the dynamic behaviour of the mount. A series of tests was conducted on the prototype mount built for this study, in order to characterize the changes occurring as a result of changing electrical current to the mount. The results of this study show that increasing electrical current to the mount, which increases the yield stress of the MR fluid, will result in an increase in both stiffness and damping of the mount. The results also show that the mount hysteresis increases with increase in current to the MR fluid, causing changes in stiffness and damping at different input frequencies.

Author(s):  
Shuo Wang ◽  
Mohammad Elahinia ◽  
The Nguyen

With the advent of alternative energy and hybrid vehicles come new vibration problems and challenges that require nontraditional solutions. Semi-active vibration isolation devices are preferred to address the problem due to their effectiveness and affordability. A magnetorheological (MR) fluid mount can provide effective vibration isolation for applications such as hybrid vehicles. The MR fluid can produce different levels of damping when exposed to different levels of magnetic field. The fluid can be working in three modes which are the flow mode, shear mode and squeeze mode. A mixed mode MR fluid mount was designed to operate in a combination of the flow mode and the squeeze mode. Each of the working modes and the combined working mode has been studied. The mount’s performance has been verified in simulation and experiments. Based on the simulation and experimental results, it can be seen that the mount can provide a large range of dynamic stiffness. Given this range of dynamic stiffness, a controller has been designed to achieve certain dynamic stiffness at certain frequencies. The experiments are set up to realize the hardware-in-the-loop tests. Results from the experiments show that the mixed mode MR fluid mount is able to achieve desired dynamic stiffness which is directly related to vibration transmissibility.


1980 ◽  
Vol 22 (2) ◽  
pp. 55-58 ◽  
Author(s):  
B. C. Majumdar

A first-order perturbation method is adopted to find the dynamic behaviour of an aerostatic circular thrust bearing having a central porous insert as a restrictor. The linearized gas film stiffness and damping are derived and used to study their behaviour with other design variables.


Author(s):  
S. Siva Kumar ◽  
K.S. Raj Kumar ◽  
Navaneet Kumar

Magnetorheological (MR) fluid damper has been designed, fabricated and tested to find the stiffness and damping characteristics. Experimentally the MR damper has been tested to analyse the behaviour of MR fluid as well as to obtain the stiffness for varying magnetic field. MR damper mathematical model has been developed for evaluating dynamic response for experimentally obtained parameters. The experimental results show that the increase of applied electric current in the MR damper, the damping force will increase remarkably up to the saturation value of current. The numerical simulation results that stiffness of the MR damper can be varied with the current value and increase the damping forces with the reduced amplitude of excitation. Experimental and theoretical results of the MR damper characteristics demonstrate that the developed MR damper can be used for vibration isolation and suppression.


2015 ◽  
Vol 752-753 ◽  
pp. 913-917
Author(s):  
Gong Yu Pan ◽  
Qian Qian Wang ◽  
Xin Yang

In order to improve the vibration isolation performance of engine mount, a new type of magneto-rheological semi-active mount with multiple inertia tracks is designed based on the existing magneto-rheological semi-active mount . The mechanical model is established according to the mount. The expression of the dynamic stiffness and damping lag angle is deduced, then the dynamic characteristics is simulated in the simulation software. At the same time, verify this model correct by the experiments.


Author(s):  
Constantin Ciocanel ◽  
The Nguyen ◽  
Christopher Schroeder ◽  
Mohammad H. Elahinia

The paper investigates the response of a magnetorheological (MR) fluid based mount that combines the squeeze and flow modes in operation. The mount governing equations are introduced and the effect of system parameters on its performance is analyzed. The proposed design yields a high static and a low dynamic stiffness in the working frequency range of the mount. The overall vibration isolation characteristic of the mount is enhanced if compared to that of existing hydraulic mounts. Displacement and/or force transmissibility can be isolated or significantly reduced, in real time, by controlling the MR fluid yield stress. An embedded electromagnet is used to activate the MR fluid that can work in either squeeze or flow modes, or in both simultaneously. The results indicate that the flow mode is less effective in reducing transmissibility than the squeeze mode. However, when the flow and squeeze modes are both activated, the effect of the flow mode becomes more obvious.


2014 ◽  
Vol 988 ◽  
pp. 332-337
Author(s):  
Hong Yun Wang ◽  
Xiang Kun Zeng ◽  
Ji Yong Zhao

Tensioners play a predominant role in the dynamic behavior of serpentine belt drive systems. The experimental set-up was carried out to study the dynamic characteristics of tensioner. Experimental results illustrate that tensioner shows hysteresis nonlinear dynamic characteristics, and dynamic stiffness and damping of slip motion of up stroke of tensioner are related to excitation frequency and amplitude. The first differential nonlinear model of tensioner was determined, and the parameter identification method of the model was introduced. The accurate of the nonlinear model and effectiveness of the parameter identification method was validated.


Author(s):  
W H Zhang ◽  
G M Mei ◽  
X J Wu ◽  
L Q Chen

To study the dynamic behaviour of pantographs, a hybrid simulation method has been used. A special test facility, which is used to simulate the dynamic performance of a pantograph when it runs through the overhead line, is established and described in this paper. As the catenary is difficult to be modelled by a hardware test facility indoor, a mixed theoretical-experimental technique is used in test facility. On the basis of the set-up of hybrid simulation test device of the pantograph-catenary system, the dynamic behaviours of four types of pantographs running along the overhead equipment at different running speeds are examined and compared. Meanwhile, the dynamic parameters such as mass, stiffness, and damping of four pantographs are measured using the hybrid simulation test facility. On the basis of these parameters, the dynamic behaviours of the four pantographs are analysed.


2013 ◽  
Vol 198 ◽  
pp. 615-620
Author(s):  
Igor Maciejewski

In this paper a method for shaping the dynamic characteristics of vibration isolation systems is presented. The multi-criteria optimisation procedure is utilized in order to find the Pareto-optimal system configuration with simultaneous minimization of conflicted optimisation criteria: the isolated body acceleration and suspension travel. As an example of the proposed method, the seat with a pneuma-hydraulic suspension is investigated and its vibro-isolation properties are shaped by an appropriate selection of the system characteristics. The basic findings of the paper consist in the optimisation procedure that takes into account the nonlinear dynamic behaviour of vibration isolation systems.


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