PAYLOAD/LAUNCHER VIBRATION ISOLATION: MR DAMPERS MODELING WITH FLUID COMPRESSIBILITY AND INERTIA EFFECTS THROUGH CONTINUITY AND MOMENTUM EQUATIONS

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1534-1541 ◽  
Author(s):  
PIERRICK JEAN ◽  
ROGER OHAYON ◽  
DOMINIQUE LE BIHAN
Keyword(s):  
Vibration Isolation ◽  
Solid Mechanics ◽  
Mr Damper ◽  
Vibration Isolator ◽  
Inertia Effects ◽  
Mr Dampers ◽  
Preliminary Study ◽  
Magneto Rheological ◽  
Theoretical Results ◽  
Fluid Compressibility

During launching, a payload is submitted to large vibrations, which may damage it. To get rid of the problem, a solution would be to put an appropriate vibration isolator at the payload/launcher interface. Thus, a soft Isolating Payload Attach Fitting (IPAF) using Magneto-Rheological (MR) dampers is envisaged. In a pre-design phase for the launcher application, a preliminary study of the behaviour of a commercial MR damper (RD-1005-3) and its use in a 1-dof vibration isolator is carried out. In this paper, we report the MR damper behaviour analysis based on fluid and solid mechanics equations. In particular, we investigate chambers fluid compressibility and inertia effects. Then the damper model is used to evaluate the performance of a MR isolator in terms of equivalent transmissibility in passive mode and using skyhook control. The theoretical results will be soon compared to those from an experimental bench in construction.

A Reliability Assessment Model for MR Damper Components within a Smart Structural Control Scheme

2008 ◽  
Vol 56 ◽  
pp. 218-224
Author(s):  
Maguid H.M. Hassan
Keyword(s):  
Structural Control ◽  
Inverse Dynamics ◽  
Mr Damper ◽  
Assessment Model ◽  
Resistance Force ◽  
Mr Dampers ◽  
Control Scheme ◽  
Smart Control ◽  
Control Devices ◽  
Magneto Rheological

Smart control devices have gained a wide interest in the seismic research community in recent years. Such interest is triggered by the fact that these devices are capable of adjusting their characteristics and/or properties in order to counter act adverse effects. Magneto-Rheological (MR) dampers have emerged as one of a range of promising smart control devices, being considered for seismic applications. However, the reliability of such devices, as a component within a smart structural control scheme, still pause a viable question. In this paper, the reliability of MR dampers, employed as devices within a smart structural control system, is investigated. An integrated smart control setup is proposed for that purpose. The system comprises a smart controller, which employs a single MR damper to improve the seismic response of a single-degree-of-freedom system. The smart controller, in addition to, a model of the MR damper, is utilized in estimating the damper resistance force available to the system. On the other hand, an inverse dynamics model is utilized in evaluating the required damper resistance force necessary to maintain a predefined displacement pattern. The required and supplied forces are, then, utilized in evaluating the reliability of the MR damper. This is the first in a series of studies that aim to explore the effect of other smart control techniques such as, neural networks and neuro fuzzy controllers, on the reliability of MR dampers.

Application of Magneto Rheological Dampers for Controlling Shock Loading

1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor ◽  
Jason M. Gooch
Keyword(s):  
Dynamic System ◽  
Shock Loading ◽  
Closed Loop ◽  
Shock Absorber ◽  
Mr Damper ◽  
Test Results ◽  
Closed Loop System ◽  
Mr Dampers ◽  
Shock Dynamics ◽  
Magneto Rheological

Abstract This study will examine the effectiveness of magneto-rheological (MR) dampers for controlling shock dynamics. Using a system that includes a 50-caliber rifle and a magneto-rheological damper, it is experimentally shown that MR dampers can be quite effective in controlling the compromise that commonly exists between shock forces and strokes across the shock absorber mechanism. A series of tests are conducted to demonstrate that different damping forces by the MR damper can result in different shock-force/stroke profiles. The test results further show that MR dampers can be used in a closed-loop system to adjust the shock loading characteristics in a manner that fits the dynamic system constraints and requirements.

A Non Parametric Model for Magneto Rheological Dampers

1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
Xubin Song
Keyword(s):  
Test Data ◽  
Mr Damper ◽  
Parametric Model ◽  
Parametric Models ◽  
Magnetic Saturation ◽  
Mr Dampers ◽  
Electro Magnetic ◽  
Magneto Rheological ◽  
Force Characteristics ◽  
Non Parametric

Abstract A non-parametric model for magneto-rheological (MR) dampers is presented. After discussing the merits of parametric and non-parametric models for MR dampers, the test data for a MR damper is used to develop a non-parametric model. The results of the model are compared with the test data to illustrate the accuracy of the model. The comparison shows that the non-parametric model is able to accurately predict the damper force characteristics, including the damper non-linearity and electro-magnetic saturation. It is further shown that the parametric model can be numerically solved more efficiently than the parametric models.

Vibration Control of a New Bed Stage System for Ambulance Using MR Dampers

2014 ◽  
Author(s):  
Hee-Dong Chae ◽  
Seung-bok Choi ◽  
Jong-Seok Oh
Keyword(s):  
Mathematical Model ◽  
Vibration Control ◽  
Vibration Isolation ◽  
Design Parameters ◽  
Ride Quality ◽  
Vibration Level ◽  
Mr Dampers ◽  
Secondary Damage ◽  
Stage System ◽  
Magneto Rheological

This paper proposes a new bed stage for patients in ambulance vehicle in order to improve ride quality in term of vibration control. The vibration of patient compartment in ambulance can cause a secondary damage to a patient and a difficulty for a doctor to perform emergency care. The bed stage is to solve vertical, rolling, and pitching vibration in patient compartment of ambulance. Four MR (magneto-rheological) dampers are equipped for vibration isolation of the stage. Firstly, a mathematical model of stage is derived followed by the measurement of vibration level of patient compartment of real ambulance vehicle. Then, the design parameters of bed stage is undertaken via computer simulation. Skyhook, PID and LQR controllers are used for vibration control and their control performances are compared.

Magnetorheological damper behaviour in accordance with flow mode

2018 ◽  
Vol 84 (2) ◽  
pp. 21101
Author(s):  
Joanes Berasategui ◽  
Ainara Gomez ◽  
Manex Martinez-Agirre ◽  
Maria Jesus Elejabarrieta ◽  
M. Mounir Bou-Ali
Keyword(s):  
Rheological Behaviour ◽  
Mr Damper ◽  
Experimental Tests ◽  
Magnetorheological Damper ◽  
Flow Mode ◽  
Main Design ◽  
Mr Dampers ◽  
Significant Parameter ◽  
Optimal Flow ◽  
Theoretical Results

The objective of this article is to determine the optimal flow mode in an MR damper to maximize its performance. Flow mode is one of the main design issues in an MR damper, as it determines the velocity profile and the pressure drop across the gap. In this research, two MR dampers were designed and manufactured with two flow modes: valve and mixed. The response of these two dampers was compared experimentally. Additionally, the experimental tests were correlated by theoretical results that were obtained considering the rheological behaviour of the MR fluid, the shear stress distribution in the gap, and the damper movement. Interestingly, the obtained results suggest that flow mode is not a significant parameter for determining the behaviour of a MR damper.

A Magnetorheological Vibration Isolator for Hydraulic Hybrid Vehicles

2005 ◽  
Author(s):  
The M. Nguyen ◽  
Mohammad H. Elahinia
Keyword(s):  
Vibration Isolation ◽  
Fuel Efficiency ◽  
Mr Damper ◽  
Hybrid Vehicles ◽  
Noise And Vibration ◽  
Variable Yield ◽  
Carrier Fluid ◽  
Mr Dampers ◽  
Hydraulic Hybrid ◽  
Motor Component

This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHV). The hybrid subsystem can potentially improve the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. High pressure hydraulic fluid “assists” the engine in the initial acceleration period. Noise and vibration are an issue with these systems due to the variable hydraulic loads that are applied to the regenerative hybrid element. This study looks into the possibility of reducing the transmitted noise and vibration to the vehicle’s chassis by using smart magnetorheological (MR) dampers. MR dampers utilize MR fluid which is made of pure iron particles suspended in a carrier fluid. MR fluids deliver variable yield stress under the effect of a controllable electromagnetic field. To this end, an MR damper is modeled and simulated. In the simulation both shock and vibration loads are considered. The simulation results are compared with the performance of regular elastomer isolators. It is shown that the MR damper can effectively reduce the vibration for different working cycles of the regenerative system.

Passenger Comfort Analysis in an Automotive Considering a Magneto-Rheological Damper based Suspension

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
R.B. Soujanya ◽  
D.D. Jebaseelan ◽  
S. Kannan
Keyword(s):  
Ride Comfort ◽  
Mr Damper ◽  
Nonlinear Behaviour ◽  
Passive Damping ◽  
Damping Force ◽  
The Road ◽  
Mr Dampers ◽  
Moving Vehicles ◽  
Magneto Rheological ◽  
Multi Body

Passenger’s comfort in moving vehicles depends on the quality of the ride. The major cause of discomfort is the vibration transmitted to passengers due to the road irregularities. For a comfortable ride on a vehicle, vibration must stay within prescribed standards. In the present work, an attempt was made to show that, the vibrations can be limited with the use of Magneto-rheological (MR) dampers for varying road profiles than the passive damping methods. MR dampers are semi-active control devices that use MR fluids to produce controllable damping force as they are known to exhibit nonlinear behaviour. Multi body dynamic studies were done to study the response of the system using a quarter car model. In this paper, passive damping (viscous damping) was considered at natural frequency of 1.012Hz, the response of damping was observed after 10s and the acceleration was found to be 6m/s2. When MR damper is employed as the magnetic force increases, the response of the damping was better than the passive damping, at 1.2A it comes down to 0.55m/s2, and the vibration gets dampened after 1.75s. Hence, from this study it is concluded that the MR damper can be employed in automobile for better ride comfort.

Experimental Approach for Finding the Response Time of MR Dampers for Vehicle Applications

2003 ◽  
Author(s):  
Fernando D. Goncalves ◽  
Jeong-Hoi Koo ◽  
Mehdi Ahmadian
Keyword(s):  
Response Time ◽  
Time Constant ◽  
Constant Velocity ◽  
Mr Damper ◽  
Initial State ◽  
Final State ◽  
Mr Dampers ◽  
Automotive Suspension ◽  
Magneto Rheological ◽  
Time Required

This paper offers a method and an experimental example of determining the response time of Magneto-Rheological (MR) dampers. The response time of MR dampers for automotive suspension applications is valuable information because it is one of the key factors that determine the practical effectiveness of the use of MR dampers in vehicles. However, a detailed description of the response time of MR dampers is seldom given in the literature. Furthermore, the methods of computing the response time are not discussed in detail. Therefore, this study intends to develop a method for experimental determination of the response time of MR dampers for automotive suspensions. A triangle wave that maintains a constant velocity across the damper is proposed as the input to use in experiments. This triangle wave ensures a constant velocity across the damper in order to accurately evaluate the response time of the MR damper. The response time was defined as the time required to make the transition from the initial state to 63.2% of the final state, or one time constant. The time constant is a measure of how long it takes a system to respond to a given input. In other words, the response time is the time necessary for the damper to achieve the desired force upon activation. To demonstrate the method, the response time was found for an MR damper particularly designed and fabricated for vehicle applications. Two cases were considered: activation response time of the damper and deactivation response time of the damper. Both cases were studied during the rebound stroke of the damper. It was found that the response time of the MR damper under activation and deactivation was 15.4 ms and 13.9 ms respectively. The results are comparable to those found in the literature.

scholarly journals Vibration modeling of a vehicle equipped with MR damper and aerodynamic elements

2019 ◽  
Vol 20 (1-2) ◽  
pp. 57-61
Author(s):  
Wiesław Grzesikiewicz ◽  
Michał Makowski
Keyword(s):  
High Speed ◽  
Mr Damper ◽  
Road Surface ◽  
Vehicle Model ◽  
Numerical Investigations ◽  
The Road ◽  
Mr Dampers ◽  
On The Road ◽  
Magneto Rheological ◽  
Vibration Modeling

We considered of a vehicle model equipped with controlled magneto-rheological (MR) dampers and controlled aerodynamic elements. The vibrations of the vehicle moving at high speed during acceleration and braking are analysed. The purpose of this analysis is to determine the effect of forces generated on aerodynamic elements on vehicle vibrations and changes in wheel pressure on the road surface during acceleration and braking. The presented work presents the results of numerical investigations obtained on the basis of the developed vehicle model.

Sign in / Sign up

Export Citation Format

Share Document