Magnetorheological fluid technology has gained significant development during the past decades. The application of magnetorheological fluids has grown rapidly in civil engineering, safety engineering, transportation, and life science with the development of magnetorheological fluid–based devices, especially magnetorheological fluid dampers. The magnetorheological fluid dampers could offer an outstanding capability in semiactive vibration control due to excellent dynamical features such as fast response, environmentally robust characteristics, large force capacity, low power consumption, and simple interfaces between electronic input and mechanical output. To address the fast growing demand on magnetorheological fluid damping technology in extensive engineering practices, the state-of-the-art development is presented in this article, which provides a comprehensive review on the structure design and its analysis of magnetorheological fluid dampers (or systems). This can be regarded as a useful complement to...

Magnetorheological fluid dampers: A review on structure design and analysis

Vehicle system dynamics integration encompasses interdisciplinary challenges innovations in various aspects related to vehicle system/subsystems/components dynamic characteristics, modeling and validation, vehicle dynamics state measurement and estimation, vehicle/chassis control systems, coordination of power management and dynamics/stability control, etc [1-4]. These are becoming more critical due to the increasing concern and rapid development in electric and hybrid vehicles, which tend to exhibit different vehicle dynamics/stability and control characteristics when compared to conventional vehicles.

Mechanical systems and signal processing

An adaptive unsaturated bistable stochastic resonance method and its application in mechanical fault diagnosis

Smart materials are kinds of designed materials whose properties are controllable with the application of external stimuli such as the magnetic field, electric field, stress, and heat. Smart materials whose rheological properties are controlled by externally applied magnetic field are known as magneto-rheological materials. Magneto-rheological materials actively used for engineering applications include fluids, foams, grease, elastomers, and plastomers. In the last two decades, magneto-rheological materials have gained great attention of researchers significantly because of their salient controllable properties and potential applications to various fields such as automotive industry, civil environment, and military sector. This article offers a recent progressive review on the magneto-rheological materials technology, especially focusing on numerous application devices and systems utilizing magneto-rheological materials. Conceivable limitations, challenges, and comparable advantages of applying these magn...

A state of art on magneto-rheological materials and their potential applications:

An improved Artificial Neural Network using Arithmetic Optimization Algorithm for damage assessment in FGM composite plates

An optimal fuzzy disturbance observer-enhanced sliding mode controller (FDO-SMC) for magneto-rheological damper (MRD)-based semi-active train-car suspensions (MRD-TSs) subjected uncertainty and disturbance (UAD) whose variability rate may be high but bounded is proposed. The two main parts of the FDO-SMC are an adaptive sliding mode controller (aSMC) and an optimal fuzzy disturbance observer (oFDO). First, initial structures of the sliding mode controller (SMC) and disturbance observer (DO) are built. Adaptive update laws for the SMC and DO are then set up synchronously via Lyapunov stability analysis with a used parameter constraint mechanism. An optimal fuzzy system (oFS) is designed to implement fully the constraint mechanism so as to guarantee for the stable converging to the desired state even if the UAD variability rate increases in a given range. As a result, the aSMC and the oFDO are created from the SMC and DO. The compared simulation surveys reflected that the positive competence to stamp out and isolate vibration with the lower consumed power is the main advantage of the proposed controller.

Designing optimal fuzzy-compensator-enhanced sliding controller for train-car semi-active suspensions

Electrohydraulic servo valves have been widely used in various automatic systems which need high precision of flow rate or pressure control to provide excellent static and dynamic control performance. The servo valves are generally classified into single-stage valve and two-stage valve. Direct drive servo valve (DDV) is a kind of single-stage valve in which the actuator is directly connected to the spool of the valve. In the conventional DDVs, the spool is generally actuated by electromagnetic actuator. Therefore, performance characteristics such as the accuracy and bandwidth of the DDVs are limited due to the inherent characteristics of the actuator. In this paper, a new type of the DDV operated by piezostack actuator is proposed and the goal of the proposed DDV is to achieve an accurate control of the flow rate at high frequency. The proposed DDV consists of a piezostack actuator, a lever mechanism to amplify displacement from the piezostack actuator and a spool part. A dynamic model of piezostack driven DDV system is derived by considering the flow force. After formulating the governing equation of the piezostack driven DDV system, a sliding mode control algorithm is designed to enforce the spool position to the desired position trajectories by activating the piezostack actuator. For the computer simulation, the specific geometric dimensions of the spool are chosen in order to achieve operation requirements: spool motion amplitude: over than 0.5mm; flow rate: over than 12liter/min; operating frequency: over than 200Hz. After confirming the maximum displacement of the spool and the flow rate of the valve at 200Hz, control performances are evaluated in time domain.

Design and control of direct drive servo-valve operated by the piezostack actuator

<abstract>We extend the so-called universal potential estimates of Kuusi-Mingione type (J. Funct. Anal. 262: 4205–4269, 2012) to the singular case $ 1 < p\leq 2-1/n $ for the quasilinear equation with measure data

<disp-formula> <label/> <tex-math id="FE1"> \begin{document}$ \begin{equation*} -\operatorname{div}(A(x,\nabla u)) = \mu \end{equation*} $\end{document} </tex-math></disp-formula>

in a bounded open subset $ \Omega $ of $ \mathbb{R}^n $, $ n\geq 2 $, with a finite signed measure $ \mu $ in $ \Omega $. The operator $ \operatorname{div}(A(x, \nabla u)) $ is modeled after the $ p $-Laplacian $ \Delta_p u: = {\rm div}\, (|\nabla u|^{p-2}\nabla u) $, where the nonlinearity $ A(x, \xi) $ ($ x, \xi \in \mathbb{R}^n $) is assumed to satisfy natural growth and monotonicity conditions of order $ p $, as well as certain additional regularity conditions in the $ x $-variable.</abstract>

Universal potential estimates for $ 1 < p\leq 2-\frac{1}{n} $

In this research, a high compact configuration of brake featuring MR fluid (MRB) is proposed. The proposed MRB consists of a rotor with multiple trapezoidal teeth acting at multiple magnetic poles of the brake. Two counter coils are placed on each side-housing of the brake. The inner face of each side-housing also has trapezoidal shape mating with the trapezoidal teeth of the rotor via MRF layer. By applying counter currents to the two coils, a magnetic fluid is generated with magnetic flux going across the MRF layer (MRF duct) between the rotor teeth and their mating poles on the housing. By using multiple poles with trapezoidal shape, a high braking torque of the brake is expected while the size of the brake is still kept to be compacted.
 After a review of MRB state of the art, configuration of the proposed MRB is presented. The modeling of the actuator is then derived based on Bingham rheological model of MRF and magnetic finite element analysis (FEA). The optimal design of the MRB is then performed in order to minimize the mass of the MRB when braking torque is constrained to be greater than a required value. From the optimal design result, performance characteristics of the actuator is simulated and compared with previously developed MRB.

Development of a novel magneto-rheological brake with multiple pole rotor

This paper presents the design of ultrasonic vibrator utilizing a piezoelectric actuator. After describing a geometric configuration of the proposed atomizer, an analytical model of the ultrasonic atomizer is formulated by considering liquid film surface theory and wave theory. The dynamic analysis is then undertaken using a finite element analysis to determine principal longitudinal vibration modes. An optimization is performed by taking the amplitude of the tip displacement as an objective function. The fluid flow characteristics of the proposed atomizer is also analyzed under operating conditions through commercial software FLUENT.

Quoc Hung Nguyen

Papers

Designing optimal fuzzy-compensator-enhanced sliding controller for train-car semi-active suspensions

Design and control of direct drive servo-valve operated by the piezostack actuator

Universal potential estimates for $ 1 < p\leq 2-\frac{1}{n} $

Development of a novel magneto-rheological brake with multiple pole rotor

Design of Ultrasonic Vibrator for Conformal Coating Spray in LED Packaging