In this article, an MR valve possessing simultaneously annular fluid flow resistance channels and radial fluid flow resistance channels is designed, and its structure and working principle are described. In addition, a mathematical model for the MR valve with both annular and radial flow paths is developed and the simulation is carried out to evaluate the newly developed MR valve. The simulation results based on the proposed model indicate that the efficiency of the MR valve with circular disk-type fluid resistance channels is superior to that with annular fluid resistance channels under the same magnetic flux density and outer radius of the valve. Furthermore, the results also show that the efficiency of the MR valve can be improved significantly with two types of fluid flow resistance gaps, viz. annular fluid flow resistance gaps and circular disk-type fluid flow resistance gaps simultaneously.

Design and modeling of a magnetorheological valve with both annular and radial flow paths

Biodiesel for HCCI engine: Prospects and challenges of sustainability biodiesel for energy transition

This study aims to observe the magnitude of the Magnetorheological Fluids (MRFs) pressure due to the application of a magnetic field. This was accomplished by placing the MRFs in a U-shaped tube, then applying a magnetic field generated by a magnetic coil. A finite element simulation for the magnetic field was carried out to estimate the magnetic field strength generated by the coil variable to the current input given in the simulated apparatus. Changes in MRFs pressure were recorded using a data logger to better observe the fluid pressure phenomena occurring in the MRFs with respect to current input variations. The results showed that the magnetic field influences the MRFs fluid pressure proportionally. The slope is not constant as the magnetic field effect to the fluid pressure gets stronger when the current input is higher. However, there are also an adverse effect of heat generated in the coil in higher current, which results in coil performance degradation and reduces the magnetic field strength.

Magnetically-Induced Pressure Generation in Magnetorheological Fluids under the Influence of Magnetic Fields

The objective of this paper is to study the performance of a sixth order polynomial approach to model hysteresis behaviour of a magnetorheological (MR) damper under harmonic excitations.The polynomial model is developed based on curve fitting from the experimental results and consists of a pair subsystem namely positive and negative acceleration which correspond to the upper and lower curves.The performance of the proposed polynomial model is compared with a well known non-parametric technique namely inverse model.The energy dissipated and equivalent damping coefficient of the MR damper in terms of input current and displacement amplitude are investigated.From the simulation results,the sixth order polynomial model shows better performance in describing non-linear hysteresis behaviour of the MR damper compared with inverse model.The force tracking control in both simulation and experimental studies demonstrate that a close-loop PI control has the ability to track the desired damping force well.

Modelling,Characterisation And Force TrackingControl Of A Magnetorheological Damper UnderHarmonic Excitation

Building structures are vulnerable to the shocks caused by earthquakes. Buildings that have been destroyed by an earthquake are very detrimental in terms of material loss and mental trauma. However, technological developments now enable us to anticipate shocks from earthquakes and minimize losses. One of the technologies that has been used, and is currently being further developed, is a damping device that is fitted to the building structure. There are various types of damping devices, each with different characteristics and systems. Multiple studies on damping devices have resulted in the development of various types, such as friction dampers (FDs), tuned mass dampers (TMDs), and viscous dampers (VDs). However, studies on attenuation devices are mostly based on the type of system and can be divided into three categories, namely passive, active, and semi-active. As such, each type and system have their own advantages and disadvantages. This study investigated the efficacy of a magnetorheological (MR) damper, a viscous-type damping device with a semi-active system, in a simulation that applied the damper to the side of a building structure. Although MR dampers have been extensively used and developed as inter-story damping devices, very few studies have analyzed their models and controls even though both are equally important in controlled dampers for semi-active systems. Of the various types of models, the Bingham model is the most popular as indicated by the large number of publications available on the subject. Most models adapt the Bingham model because it is the most straightforward of all the models. Fuzzy controls are often used for MR dampers in both simulations and experiments. This review provides benefits for further investigation of building damping devices, especially semi-active damping devices that use magnetorheological fluids as working fluids. In particular, this paper provides fundamental material on modeling and control systems used in magnetorheological dampers for buildings. In fact, magnetorheological dampers are no less attractive than other damping devices, such as tuned mass dampers and other viscous dampers. Their reliability is related to the damping control, which could be turned into an interesting discussion for further investigation.

Review of Magnetorheological Damping Systems on a Seismic Building

Formula Student is a prestigious competition for engineering student which enables students doing design, analysis, and fabricating a full-scale formula-style vehicle. One of the most important parameters of the formula vehicle is power to weight ratio. Based on this parameter, the vehicle must have the highest power with lowest vehicle weight. Chassis have a big role in the vehicle weight; thus, it must have as low weight as possible but maintaining good strength. This article focuses on the development of third-generation chassis based on the previous generation. The chassis strength is firstly evaluated using finite element analysis. During simulation, the strength of 3 types of chassis (1st, 2nd, and 3rd generations) are studied their torsional strength. The obtained results are then compared to each chassis weights. Based on this approach, the ratio between torsional stiffness and weight of all chassis can be compared. All chassis are designed using same material and joint method, whilst the differences are amount of frame member, dimension, and structure layout. The simulation results show that the torsional stiffness to weight ratio is 15.39, 24.03, and 25.12 Nm/deg kg respective to 1st, 2nd, and 3rd generation. It can be concluded that the 3rd generation has the highest stiffness to weight ratio so far.

Improvement of Space Tube Frame for Formula Student Vehicle

This case study proposes the development of damping technology using intelligent materials as working fluids for the landing gear of Unmanned Aerial Vehicles (UAV) during the landing process. The intelligent materials to be used are magnetorheological fluids (MRF), a liquid that has variable viscosity to magnetic fields. This intelligent material can improve the performance of the damping device by allowing it to have variable damping features through viscosity changing. The proposed UAV magnetorheological (MR) dampers design utilizes a magnetic valve that has an annular flow channel configuration with a 0.5 mm gap size equipped with an electromagnetic coil with adjustable current input. Both gap size and the current input selection affect the performance of the damping device. This study discusses the performance to reduce shock during the landing process. The performance is evaluated by analyzing the pressure drop and damping force produced by the device with changes in the current input variation. The numerical and simulation results show that the damping characteristics of the device could be adjusted by changing the current input to the electromagnet. The obtained results are then adjusted based on the needs of the UAV in landing purposes. The study proved that the device performance is suitable to absorb shock during the landing process of the UAV.

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A New Magnetorheological Fluids Damper for Unmanned Aerial Vehicles

Magnetorheological elastomers (MRE)-based products are usually located in an area directly exposed to sunlight and rain. However, there is no specific research on the behavior of MRE after accelerated weathering. Therefore, in this study, the changes to the chemical and rheological properties of both isotropic and anisotropic MRE after accelerated weathering were examined. Treated and untreated specimens were compared. MRE specimens with 40% by weight CIP were prepared with no current excitation and another sample was prepared with 1.5 T of magnetic flux density. Each specimen was treated in an accelerated weathering machine, Q-Sun Xe-1 Xenon Test Chamber, under a UV light exposure cycle and water spray. A material characterization was carried out using FTIR and a rheometer to determine the changes to the chemical and rheological properties. The morphological analysis results showed that after the weather treatment, the surface was rough and more cavities occurred. The rheometer test results showed a significant decrease in the storage modulus of each treated MRE specimen, unlike the untreated MRE specimens. The decrease in the storage modulus value with currents of 0, 1, 2, and 3 Amperes was 66.67%, 78.9%, 85.2%, and 80.5%, respectively. Meanwhile, FTIR testing showed a change in the wave peak between the untreated and treated MRE specimens. Thermogravimetric analysis (TGA) also showed a decrease in MRE weight for each specimen. However, for both treated and untreated MRE specimens, the decrease in TGA was not significantly different. In all the tests carried out on the MRE samples, weather acceleration treatment caused significant changes. This is an important consideration for developers who choose silicone as the MRE matrix.

Declining Performance of Silicone-Based Magnetorheological Elastomers after Accelerated Weathering.

This article delivered an innovative idea of a magnetorheological (MR) damper for secondary suspension of train bogie. The valve inside MR damper adopted meandering of both fluid flow and magnetic flux for improving magnetization area. In this work, the design and working principle of the MR valve were presented including a mathematical model to predict the pressure drop. In the early stage, the finite element method magnetics software (FEMM) simulation could predict the magnetic flux density across the passages. Based on the amount of magnetic flux, the corresponding shear yield stress could be determined from its basic physical properties. The mathematical model covered pressure drop prediction for both off-state and on-state. The FEMM simulation results showed that the meandering flow and serpentine flux design could improve the effective area of magnetization. Consequently, the pressure drop of the valve could have wider ranges and achieve a high value of pressure differences. This result could be potentially improving the performance of the damping forces of the lateral damper in a bogie train.

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Bhre Wangsa Lenggana

Papers

Improvement of Space Tube Frame for Formula Student Vehicle

Review of Magnetorheological Damping Systems on a Seismic Building

A New Magnetorheological Fluids Damper for Unmanned Aerial Vehicles

Declining Performance of Silicone-Based Magnetorheological Elastomers after Accelerated Weathering.

An Innovative Design of Magnetorheological Lateral Damper for Secondary Suspension of a Train