Dynamic Behavior Of Magnetorheological Damper Research Articles

Characterization and quarter car analysis with magnetorheological fluid damper using modified algebraic model (mAlg)

Magnetorheological (MR) dampers have received the ever-increasing attention of many researchers considering their wide range of applications ranging from large seismic control of structures to prosthetics in the medical field. One such application is in semi-active vehicle suspension with MR damper. Modeling the dynamic behavior of MR damper is an intriguing challenge and many mathematical models are put forth to address this task. In this work, the MR damper is initially developed and characterized using in-house prepared MR fluid. This study aims at using a modified algebraic model (mAlg) for modeling the hysteretic behavior of the MR damper using experimental force data. Also, the study uses a Genetic algorithm toolbox to find optimal parameters for the mAlg model, and the accuracy of mAlg is visualized with various plots. The work also aims at analyzing the response of the quarter car model with MR damper to three kinds of road excitations using Simulink.

Insight into the response time of fail-safe magnetorheological damper

The significant problem of magnetorheological (MR) dampers is their poor fail-safe ability. In the case of power supply failure, the damper remains in a low damping state which is dangerous for several technical applications. This can be solved by accommodating a permanent magnet to the magnetic circuit of the damper. Currently, the MR dampers are used in progressive semiactive (S/A) control of suspension systems. The dynamics (force response time) of the damper is an important parameter that affects the performance of S/A control. The main goal of this paper is to introduce the dynamic behavior of MR damper with a permanent magnet. The damper design with the permanent magnet in the magnetic circuit, transient magnetic simulation including magnetic hysteresis and eddy currents, and experiments are presented. The magnetic field response time and MR damper force response time are measured and also determined from magnetic simulation. The permanent magnet significantly influences the MR damper dynamics. The decrease of the damping force from a fail-safe state–medium damping to off-state–low damping is significantly faster (2 ms, −1 A) than the increase to on-state–high damping (12 ms, 1 A). The exact value is depending on the electric current magnitude and piston velocity. The damper achieved fail-safe damping force approximately 1/3 of the maximum damping force. The exact value of the fail-safe force is magnetization history-dependent. The maximum dynamic force range is 8.5 which is comparable with the common design of MR damper.

An Optimal NARX Neural Network Identification Model for a Magnetorheological Damper With Force-Distortion Behavior

This paper presents an optimal NARX neural network identification model for a magnetorheological (MR) damper with the force-distortion behavior. An intensive experimental study is conducted for designing the NARX network architecture to enhance modeling accuracy and availability, and the activation function selection, weights and biases of the selected network are optimized by differential evolution algorithm (DEA). Different experimental training and validation samples are used for network training. The prediction capability of the optimal NARX model is verified by new measured test data. The test and comparative results show that the optimal NARX network model can satisfactorily emulate the dynamic behavior of MR damper and effectively capture its distortion behavior occurred with the increased current. The developed inverse NARX network model can effectively estimate the required current and track desired damping force. Moreover, the effects of different noise disturbance on the NARX network model performance are analyzed, and the model error varies slightly with a small noise disturbance. The accuracy of the results supports that the use of this modelling technique for identifying irregular nonlinear models of MR damper and similar devices.

Modeling and testing of a field-controllable magnetorheological fluid damper

In this study, an experimental and a theoretical study were carried out to predict the dynamic performance of a linear magnetorheological (MR) fluid damper. After having designed and fabricated the MR damper, its dynamic testing was performed on a mechanical type shock machine under sinusoidal excitation. A theoretical flow analysis was done based on the Bingham plastic constitutive model to predict the behavior of the prototyped MR damper. The theoretical results were then validated by comparing them against experimental data, and it was shown that the flow model can accurately capture the dynamic force range of the MR damper. In addition to the flow model, a modified parametric algebraic model was proposed to capture the hysteretic behavior of the MR damper. The superiority of the proposed modified model was shown by comparing it with the Alg model as well as with a widely adopted modified Bouc–Wen model through an error analysis. It is observed that although all the three models are comparable at the excitation velocities of 0.05, 0.10, and 0.15 m/s, the mAlg model is remarkably successful at the highest excitation velocity of 0.2 m/s over the other two. The improvements in the predictions were found to be over 50%, relative to unmodified model especially at lower current inputs. Therefore, it was concluded that the present flow model can be successfully adopted to design and predict the dynamic behavior of MR dampers, while the mAlg model can be used to develop more effective control algorithms for such devices.

Stochastic and hybrid methods for the identification in the Bouc-Wen model for magneto – rheological dampers

Magneto-rheological (MR) dampers are semi-active control devices that require low power input and are considered fail-safe, i.e. in case of control hardware failure they become passive dampers. In the present work we consider a sensitivity analysis and use the deterministic gradient based Levenberg-Marquardt method, the stochastic methods Simulated Arnealing and Genetic Algorithms, as well as hybridizations of these methods, for the estimation of parameters in the Bouc-Wen model, which is used to describe the dynamic behavior of MR dampers. The parameters associated with the histeretic displacement evolution equation are the most difficult to be estimated, and therefore we use a strategy for estimating such parameters separately from other parameters of the model.

Large-scale MR fluid dampers: modeling and dynamic performance considerations

The magnetorheological (MR) damper is one of the most promising new devices for structural vibration reduction. Because of its mechanical simplicity, high dynamic range, low power requirements, large force capacity and robustness, this device has been shown to mesh well with application demands and constraints to offer an attractive means of protecting civil infrastructure systems against severe earthquake and wind loading. In this paper, an overview of the essential features and advantages of MR materials and devices is given. This is followed by the derivation of a quasi-static axisymmetric model of MR dampers, which is then compared with both a simple parallel-plate model and experimental results. While useful for device design, it is found that these models are not sufficient to describe the dynamic behavior of MR dampers. Dynamic response time is an important characteristic for determining the performance of MR dampers in practical civil engineering applications. This paper also discusses issues affecting the dynamic performance of MR dampers, and a mechanical model based on the Bouc–Wen hysteresis model is developed. Approaches and algorithms to optimize the dynamic response are investigated, and experimental verification is provided.