A Novel Magnetorheological Concentric Spiral-Flow Damper

2015 ◽  
Author(s):  
Kai Hsiang Chang ◽  
Jing Long Tong ◽  
Chou Min Chia ◽  
Kuang Yuh Huang
Keyword(s):  
Heat Dissipation ◽  
Experimental Studies ◽  
Low Frequency ◽  
Mr Damper ◽  
Flow Channel ◽  
Spiral Flow ◽  
Damping Force ◽  
Fixed Space ◽  
Novel Design ◽  
High Range

In this article, a novel design of MR damper, concentric spiral flow MR damper, is proposed. It could improve the heat dissipation problem which is usually found in traditional MR damper. The proposed MR damper has a concentric spiral flow channel around the cylinder which not only separates coils from MR fluid, but also increases the length of flow channel in a fixed space. Experimental studies has been conducted to demonstrate the performance of the proposed MR damper, the result shows the MR damper generates the maximum damping force of 188 N without applying magnetic field and 1251 N when inputting 1.5 A at low frequency, which means the damper has high range of adjustable damping force. The CSF-damper can be used to systems or structures with low dynamic response.

scholarly journals Development of a Multiple Coil Magneto-Rheological Smart Damper to Improve the Seismic Resilience of Building Structures

2020 ◽  
Vol 14 (1) ◽  
pp. 78-93
Author(s):  
Daniel Cruze ◽  
Hemalatha Gladston ◽  
Ehsan Noroozinejad Farsangi ◽  
Sarala Loganathan ◽  
Tensing Dharmaraj ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Time History ◽  
Mr Damper ◽  
Research Progress ◽  
Building Structures ◽  
Design Development ◽  
Damping Force ◽  
New Device ◽  
Active Vibration ◽  
Magneto Rheological

Introduction: The incremental research progress on Magneto-Rheological (MR) damper and its response motivated many researchers and engineers to focus on this topic in the last decade. Methods: MR damper is classified as a semi-active vibration controlling device owing to its mechanical simplicity, low power usage, large response reduction, perfect damping mechanism, good stability, quick reaction time and robust interface. Results: In the current investigation, experimental studies were performed for the design, development, and testing of a new type of MR damper. A proposed approach was adopted for the magnetic generation using multi-coils to produce more shear force in the flow gap. The study investigates time history responses of the proposed system under an array of strong ground motions at both element and structure levels. Numerical hybrid simulation using OpenSees has also been carried out on a building structure to show the effectiveness of the new device. Conclusion: The performance of the investigated structure equipped with the proposed system indicates a large reduction in displacement and an increase in damping force under major seismic events.

A comprehensive optimal design method for magnetorheological dampers utilized in DMU power package

2021 ◽  
pp. 146442072110496
Author(s):  
Fanghui Xu ◽  
Dawei Dong ◽  
Yan Huang ◽  
Rui Zhang ◽  
Shizhe Song ◽  
...  
Keyword(s):  
Optimal Design ◽  
High Frequency ◽  
High Speed ◽  
Low Frequency ◽  
Mr Damper ◽  
Magnetic Flux Density ◽  
Objective Functions ◽  
Damping Force ◽  
Optimal Method ◽  
Mr Dampers

The diesel multiple unit (DMU) has been widely used in high-speed railway service due to its flexibility and economy. Considering the broadband and complex vibration generated by DMU power package, the advanced semi-active suspension with magnetorheological (MR) dampers is introduced to promote anti-vibration performance. In this work, a comprehensive optimal design approach for MR damper used in DMU power package is proposed. Quasi-static modeling process is conducted to obtain MR damper's low-frequency outputs, while its high-frequency damping forces are calculated by physical modeling considering the fluid compressibility and piston assembly inertia. Then the objective functions and optimization variables are determined. Based on response surface and linear correlation analysis, the influence of the optimal variables on the objective functions is discussed. Using reference-point based nondominated sorting approach (NSGA-III), the evolutionary many-objective optimization is conducted. In addition, magnetic design is incorporated into the optimal process to ensure the magnetic flux density in the effective working area. Finally, an optimized MR damper prototype is manufactured and tested. By comparing the experimental damping force with calculated results in both low-frequency and high-frequency ranges, the effectiveness of the presented optimal method for MR dampers is validated.

Calculation-and-experimental estimation of the role of the frequency ratio in changing the endurance at two-frequency deformation modes

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 64-71 ◽  
Author(s):  
M. M. Gadenin
Keyword(s):  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Reduction Factor ◽  
Single Frequency ◽  
Cyclic Loads ◽  
Small Ratio ◽  
Harmonic Components ◽  
Deformation Modes

The cycle configuration at two-frequency loading regimes depends on the number of parameters including the absolute values of the frequencies and amplitudes of the low-frequency and high-frequency loads added during this mode, the ratio of their frequencies and amplitudes, as well as the phase shift between these harmonic components, the latter having a significant effect only with a small ratio of frequencies. Presence of such two-frequency regimes or service loading conditions for parts of machines and structures schematized by them can significantly reduce their endurance. Using the results of experimental studies of changes in the endurance of a two-frequency loading of specimens of cyclically stable, cyclically softened and cyclically hardened steels under rigid conditions we have shown that decrease in the endurance under the aforementioned conditions depends on the ratio of frequencies and amplitudes of operation low-frequency low-cycle and high-frequency vibration stresses, and, moreover, the higher the level of the ratios of amplitudes and frequencies of those stacked harmonic processes of loading the greater the effect. It is shown that estimation of such a decrease in the endurance compared to a single frequency loading equal in the total stress (strains) amplitudes can be carried out using an exponential expression coupling those endurances through a parameter (reduction factor) containing the ratio of frequencies and amplitudes of operation cyclic loads and characteristic of the material. The reduction is illustrated by a set of calculation-experimental curves on the corresponding diagrams for each of the considered types of materials and compared with the experimental data.

Damping characteristics of a magneto-rheological damper with dual independent controllable ducts

2021 ◽  
pp. 1045389X2110188
Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou
Keyword(s):  
Dynamic Range ◽  
Fluid Flows ◽  
Mr Damper ◽  
Viscous Damping ◽  
The Novel ◽  
The Finite Element Method ◽  
Damping Force ◽  
Damping Characteristics ◽  
Magneto Rheological ◽  
The Mathematical Model

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.

scholarly journals A smart passive MR damper with a hybrid powering system for impact mitigation: An experimental study

2021 ◽  
pp. 1045389X2098808
Author(s):  
S. Jin ◽  
L. Deng ◽  
J. Yang ◽  
S. Sun ◽  
D. Ning ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Mr Damper ◽  
Damping Force ◽  
Softening Effect ◽  
Impact Speed ◽  
Impact Mitigation ◽  
Passive Damper ◽  
Comparison Results ◽  
Wide Range ◽  
The Impact

This paper presents a smart passive MR damper with fast-responsive characteristics for impact mitigation. The hybrid powering system of the MR damper, composed of batteries and self-powering component, enables the damping of the MR damper to be negatively proportional to the impact velocity, which is called rate-dependent softening effect. This effect can keep the damping force as the maximum allowable constant force under different impact speed and thus improve the efficiency of the shock energy mitigation. The structure, prototype and working principle of the new MR damper are presented firstly. Then a vibration platform was used to characterize the dynamic property and the self-powering capability of the new MR damper. The impact mitigation performance of the new MR damper was evaluated using a drop hammer and compared with a passive damper. The comparison results demonstrate that the damping force generated by the new MR damper can be constant over a large range of impact velocity while the passive damper cannot. The special characteristics of the new MR damper can improve its energy dissipation efficiency over a wide range of impact speed and keep occupants and mechanical structures safe.

Development of a Damper Control System for Combined Cycle Thermal Gas Power Plant

2014 ◽  
Author(s):  
Amit Kumar Mondal ◽  
Vindhya Devalla ◽  
Vivek Kaundal ◽  
Kamal Bansal
Keyword(s):  
Heat Dissipation ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Solenoid Valve ◽  
Combined Cycle ◽  
Solenoid Coil ◽  
Hydraulic Damper ◽  
Wireless Control ◽  
Damper Control ◽  
Gas Power Plant

This paper addresses a technique to solve the problem of heat dissipation in solenoid coil of the solenoid valve which is controlling the hydraulic damper by using pulse width modulation (PWM) switching technique with low frequency. In addition to this damper controlling is achieved via wireless controlling. By using PWM based low frequency switching technique the gas turbine trip will be protected. PWM is achieved by microcontroller and wireless control is done by ZigBee.

Elastic-Plastic Time History Analysis of MR Damping Structure Based on LQG Algorithm

2016 ◽  
Vol 858 ◽  
pp. 145-150
Author(s):  
Yu Liang Zhao ◽  
Zhao Dong Xu
Keyword(s):  
Optimal Control ◽  
Time History ◽  
Mr Damper ◽  
Time History Analysis ◽  
Control Force ◽  
Control Effect ◽  
Damping Force ◽  
Optimal Control Strategy ◽  
Elastic Plastic ◽  
History Analysis

This paper discussed an elastic-plastic time-history analysis on a structure with MR dampers based on member model, in which the elastoplastic member of the structure is assumed to be single component model and simulated by threefold line stiffness retrograde model. In order to obtain better control effect, Linear Quadratic Gaussian (LQG) control algorithm is used to calculate the optimal control force, and Hrovat boundary optimal control strategy is used to describe the adjustable damping force range of MR damper. The effectiveness of the MR damper based on LQG algorithm to control the response of the structure was investigated. The results from numerical simulations demonstrate that LQG algorithm can effectively improve the response of the structure against seismic excitations only with acceleration feedback.

scholarly journals Water Level Sensing in a Steel Vessel Using A0 and Quasi-Scholte Waves

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Peng Guo ◽  
Bo Deng ◽  
Xiang Lan ◽  
Kaili Zhang ◽  
Hongyuan Li ◽  
...  
Keyword(s):  
Water Level ◽  
Guided Waves ◽  
Mode Conversion ◽  
Experimental Studies ◽  
Low Frequency ◽  
Steel Vessel ◽  
Theoretical Predictions ◽  
Travelling Time ◽  
The Comparative Study ◽  
Group Velocities

This paper presents a water level sensing method using guided waves of A0 and quasi-Scholte modes. Theoretical, numerical, and experimental studies are performed to investigate the properties of both the A0 and quasi-Scholte modes. The comparative study of dispersion curves reveals that the plate with one side in water supports a quasi-Scholte mode besides Lamb modes. In addition, group velocities of A0 and quasi-Scholte modes are different. It is also found that the low-frequency A0 mode propagating in a free plate can convert to the quasi-Scholte mode when the plate has one side in water. Based on the velocity difference and mode conversion, a water level sensing method is developed. For the proof of concept, a laboratory experiment using a pitch-catch configuration with two piezoelectric transducers is designed for sensing water level in a steel vessel. The experimental results show that the travelling time between the two transducers linearly increases with the increase of water level and agree well with the theoretical predictions.

Experimental and Numerical Modal Analysis of Composite Laminated Shells

2019 ◽  
Vol 161 (A1) ◽  
Keyword(s):  
Heat Dissipation ◽  
Mass Matrix ◽  
Experimental Studies ◽  
Free Vibration Analysis ◽  
Mode Shapes ◽  
Radius Of Curvature ◽  
Lumped Mass ◽  
Auxiliary Equipment ◽  
Mass Model ◽  
Laminated Shells

The presence of cut outs at different positions of laminated shell component in marine and aeronautical structures facilitate heat dissipation, undertaking maintenance, fitting auxiliary equipment, access ports for mechanical and electrical systems, damage inspection and also influences the dynamic behaviour of the structures. The aim of the present study is to establish a comprehensive perspective of dynamic behavior of laminated deep shells (length to radius of curvature ratio less than one) with cut-out by experiments and numerical simulation. The glass epoxy laminated composite shell has been prepared in the laboratory by resin infusion. The experimental free vibration analysis is carried out on laminated shells with and without cut-out. The mass matrix is developed by considering rotary inertia in a lumped mass model in the numerical modeling. The results obtained from numerical and experimental studies are compared for verification and the consistency between mode shapes is established by applying modal assurance criteria.

scholarly journals Robust H∞ Control of STMDs Used in Structural Systems by Hardware in the Loop Simulation Method

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 55
Author(s):  
Huseyin Aggumus ◽  
Rahmi Guclu
Keyword(s):  
Natural Frequencies ◽  
Experimental Studies ◽  
Mr Damper ◽  
Simulation Method ◽  
Control Element ◽  
Structural Systems ◽  
Hardware In The Loop ◽  
Building Model ◽  
Mass Damper ◽  
Set Up

This paper investigated the performance of a semi-active tuned mass damper (STMD) on a multi-degree of freedom (MDOF) building model. A magnetorheological (MR) damper was used as a control element that provided semi-activity in the STMD. The Hardware in the Loop Simulation (HILS) method was applied to mitigate the difficulty and expense of experimental studies, as well as to obtain more realistic results from numerical simulations. In the implementation of this method for the STMD, the MR damper was set up experimentally, other parts of the system were modeled as computer simulations, and studies were carried out by operating these two parts simultaneously. System performance was investigated by excitation with two different acceleration inputs produced from the natural frequencies of the MDOF building. Additionally, a robust H ∞ controller was designed to determine the voltage transmitted to the MR damper. The results showed that the HILS method could be applied successfully to STMDs used in structural systems, and robust H ∞ controls improve system responses with semi-active control applications. Moreover, the control performance of the MR damper develops with an increase in the mass of the STMD.

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