Parameter identification of modified Bouc–Wen model and analysis of size effect of magnetorheological dampers

2017 ◽  
Vol 29 (7) ◽  
pp. 1464-1480 ◽  
Author(s):  
Yongbo Peng ◽  
Jinggui Yang ◽  
Jie Li
Keyword(s):  
Size Effect ◽  
Performance Test ◽  
Functional Relationship ◽  
Excitation Frequency ◽  
Magnetorheological Damper ◽  
Input Current ◽  
Smart Devices ◽  
Model Parameters ◽  
Magnetorheological Dampers ◽  
Large Size

Magnetorheological damper is one of the most promising smart devices for vibration mitigation of structures subjected to dynamic loads. In order to fulfill the value of magnetorheological damping control, a feasible mechanical model of magnetorheological dampers with simplicity and sufficient accuracy is usually required in practice. It comes up, however, with a challenging issue for the modeling of large-size magnetorheological dampers due to physical constraints on the performance test. The large-size magnetorheological damper is typically modeled in up-scaling parameters associated with models of the small-size magnetorheological damper. This treatment remains open since a size effect hinges upon the intrinsic non-linearity inherent in the device. In this article, a dynamic test of a small-size magnetorheological damper is performed first. The relevance of damper force with the input current and excitation frequency is well revealed. The modified Bouc–Wen model is employed to logically represent the dynamic behaviors of magnetorheological dampers. Identification of model parameters in typical loading cases is then proceeded, of which the functional relationship against input current is established. The size effect of magnetorheological dampers is further addressed through investigating the functional relationship relevant to maximum outputs of 200, 10, and 5 kN. It is indicated that the small-size magnetorheological damper needs more number of control parameters than the large-size magnetorheological damper. Moreover, a linear current relevance of model parameters appears in the small-size magnetorheological damper, while a quadratic current relevance of model parameters appears in the large-size magnetorheological damper. Size effect of magnetorheological dampers arises to be well-marked in the range of low current and becomes unapparent in the range of high current. Besides, the validation of modified Bouc–Wen model is carried out that reveals the applicability of the model with case-optimized parameters.

Performance tests and mathematical model considering magnetic saturation for magnetorheological damper

2012 ◽  
Vol 23 (12) ◽  
pp. 1331-1349 ◽  
Author(s):  
Zhao-Dong Xu ◽  
Da-Huan Jia ◽  
Xiang-Cheng Zhang
Keyword(s):  
Mathematical Model ◽  
Excitation Frequency ◽  
Experimental Results ◽  
Displacement Amplitude ◽  
Magnetorheological Damper ◽  
Input Current ◽  
Magnetic Flux Density ◽  
Magnetic Saturation ◽  
Loading Frequency ◽  
Magnetorheological Dampers

As a semiactive control device, magnetorheological dampers have been paid more attention due to their high controllability, fast response, and low power demand. One of the important characteristics for magnetorheological dampers is magnetic saturation, that is, the maximum damping force will reach some value and no longer vary with the increasing input current, especially in the presence of large magnetic flux density. In order to take this problem into account fully, tests on a shear-valve mode magnetorheological damper are carried out to consider the effects of input current, displacement amplitude, and loading frequency on the properties of the magnetorheological damper during magnetic saturation situation first. Then, the magnetic saturation phenomenon of the magnetorheological damper is simulated using the finite element method, and the numerical simulation results are compared with the experimental results. Finally, a magnetic saturation mathematical model is proposed to describe the properties of the magnetorheological damper, and the numerical hysteresis curves of the proposed magnetic saturation mathematical model, the Bingham model, and the Bouc–Wen model are compared with the experimental results. It can be concluded that the magnetic saturation mathematical model can describe the influence of input current, displacement amplitude, and excitation frequency on the properties and the magnetic saturation property of the magnetorheological damper.

Testing and Modeling of MR Damper and Its Application to SDOF Systems Using Integral Backstepping Technique

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Sk. Faruque Ali ◽  
Ananth Ramaswamy
Keyword(s):  
Active Control ◽  
Testing Machine ◽  
Mr Damper ◽  
Control Device ◽  
Magnetorheological Damper ◽  
Input Current ◽  
Magnetorheological Dampers ◽  
Damper Control ◽  
Nonlinear Devices ◽  
Current Monitoring

Magnetorheological dampers are intrinsically nonlinear devices, which make the modeling and design of a suitable control algorithm an interesting and challenging task. To evaluate the potential of magnetorheological (MR) dampers in control applications and to take full advantages of its unique features, a mathematical model to accurately reproduce its dynamic behavior has to be developed and then a proper control strategy has to be taken that is implementable and can fully utilize their capabilities as a semi-active control device. The present paper focuses on both the aspects. First, the paper reports the testing of a magnetorheological damper with an universal testing machine, for a set of frequency, amplitude, and current. A modified Bouc–Wen model considering the amplitude and input current dependence of the damper parameters has been proposed. It has been shown that the damper response can be satisfactorily predicted with this model. Second, a backstepping based nonlinear current monitoring of magnetorheological dampers for semi-active control of structures under earthquakes has been developed. It provides a stable nonlinear magnetorheological damper current monitoring directly based on system feedback such that current change in magnetorheological damper is gradual. Unlike other MR damper control techniques available in literature, the main advantage of the proposed technique lies in its current input prediction directly based on system feedback and smooth update of input current. Furthermore, while developing the proposed semi-active algorithm, the dynamics of the supplied and commanded current to the damper has been considered. The efficiency of the proposed technique has been shown taking a base isolated three story building under a set of seismic excitation. Comparison with widely used clipped-optimal strategy has also been shown.

Analysis and Simulation of Machine Tool Vibration Based on Magneto-Rheological Dampers

2014 ◽  
Vol 971-973 ◽  
pp. 368-371
Author(s):  
Shang Liu ◽  
Xiao Long Zhang
Keyword(s):  
Machine Tool ◽  
Performance Test ◽  
Dynamic Performance ◽  
Structural Features ◽  
Magnetorheological Damper ◽  
Magnetorheological Dampers ◽  
Cnc Machine ◽  
And Performance ◽  
Magneto Rheological ◽  
Technical Features

The subject comesfrom major national special project in Kunming Machine Tool Factory which oursupervisor is working on currently. This report is the analysis of overallstructure of magnetorheological dampers,main technical features andperformance. It also provides a brief introduction to the main features of MRFand rheological principle, as well as the calculation of magnetorheologicaldamper size design, and also constructs the magnetorheological damper simulationmodel based on the magneto-rheological dampers structural features. With theTHM65160 CNC machine structure, we designed specifically on the localapplication of magneto-rheological dampers for varying magnetic flux dampermounted machine made ​​dynamic performance test responses. Based on this,magnetorheological dampers combine structural and performance characteristics,simulating the motion by using ADMS.

scholarly journals Full-Scale Simulations of Magnetorheological Damper for Implementation of Semi-Actively Structural Control

2018 ◽  
Vol 35 (4) ◽  
pp. 549-562 ◽  
Author(s):  
Y. B. Peng ◽  
Z. K. Zhang ◽  
J. G. Yang ◽  
L. H. Wang
Keyword(s):  
Structural Control ◽  
Low Cost ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Mr Damper ◽  
Excitation Amplitude ◽  
Full Scale ◽  
Magnetorheological Damper ◽  
Input Current ◽  
Two Dimensional

ABSTRACTFull-scale simulations of a (Magnetorheological) MR damper are carried out for revealing its hysteretic behaviors associated with implementation of semi-active control using the routine of computational fluid dynamics. By virtue of the structural symmetry of the MR damper, a two-dimensional configuration for finite element simulation is built up. Herschel-Bulkley model is employed to represent the property of the MR fluid, of which the control parameters and their relevances to the input current are addressed. Typical cases involving sinusoidal and irregular displacements, steady and transient currents loaded upon the MR damper are investigated. Numerical investigations reveal that the damper force has a positive correlation with input current, excitation amplitude and excitation frequency. The full-scale simulation is proved to exhibit a sound accuracy through the validation of experimental data. It provides a logical manner revealing the true performance of MR dampers under desirable operating modes in practice, and can be readily integrated with the gain design of the associated semi-actively controlled structure. This progress bypasses the technical challenge inherent in the traditional tests with low-frequency cyclic loadings due to the limitation of experimental setup. Besides, comparative study between two-dimensional and three-dimensional configuration simulations of the MR damper shows that former has a better applicability, which can be carried out on a low-cost platform.

Self-powered magnetorheological dampers for motorcycle suspensions

2017 ◽  
Vol 232 (7) ◽  
pp. 921-935 ◽  
Author(s):  
Chao Chen ◽  
Yu Shing Chan ◽  
Li Zou ◽  
Wei-Hsin Liao
Keyword(s):  
Laboratory Testing ◽  
Ride Comfort ◽  
Mechanical Energy ◽  
The Self ◽  
Magnetorheological Damper ◽  
System Level ◽  
Magnetorheological Dampers ◽  
Suspension Systems ◽  
Magnetorheological Suspension ◽  
Self Powered

Dampers are the parts of suspensions which improve the ride comfort and the safety of vehicles including motorcycles. Magnetorheological dampers are very attractive for motorcycle suspensions, because of their controllable properties and their fast responses. Considerable energy is wasted owing to the energy dissipation by dampers encountering road irregularities and accelerating processes during everyday use of motorcycles. In addition, the current magnetorheological suspension systems depend on the power supply of batteries. Therefore, in this paper, a self-powered magnetorheological damper for motorcycle suspensions is proposed and implemented for the first time. It can convert the wasted mechanical energy into useful electrical energy to power itself. There are great merits in this such as energy saving, independence of extra batteries and less maintenance in comparison with conventional magnetorheological suspension systems, while keeping controllable performances. A customized prototype of the self-powered magnetorheological damper that is compatible with a motorcycle is developed and actually implemented in a motorcycle. Modelling for the self-powered magnetorheological damper is developed and validated by laboratory testing. Laboratory testing showed that the self-powered feature works well to generate the electrical power and to vary the magnetorheological damping force. Preliminary system-level testing showed that a self-powered magnetorheological suspension results in a better ride comfort, compared with that of a magnetorheological suspension without power generation. The results showed that implementing self-powered magnetorheological dampers in motorcycle suspensions is feasible and beneficial.

scholarly journals Prototype of a magnetorheological damper

2018 ◽  
Vol 19 (12) ◽  
pp. 229-232
Author(s):  
Paweł Skalski
Keyword(s):  
State Of The Art ◽  
The State ◽  
Magnetorheological Damper ◽  
Patent Office ◽  
Magnetorheological Dampers ◽  
Magnetorheological Elastomer ◽  
New Construction

Paper discussed the State of the Art focused on magnetorheological dampers. Then the new construction solution of a damper with a magnetorheological elastomer was presented. The magnetorheological damper was designed in the Institute of Aviation and was intellectually protected in the Polish Patent Office. The article ends with conclusions.

Utilizing a Thermal Time Model to Estimate Safe Times to Transplant Tilia Trees

2019 ◽  
Vol 45 (5) ◽  
Author(s):  
Tapio Linkosalo ◽  
Pilvi Siljamo ◽  
Anu Riikonen ◽  
Frank Chmielewski ◽  
Juha Raisio
Keyword(s):  
Geographical Area ◽  
Frost Damage ◽  
Thermal Time ◽  
Weather Data ◽  
Model Parameters ◽  
The European Union ◽  
Time Model ◽  
Large Size ◽  
Nursery Trees ◽  
Thermal Time Model

City trees planted in parks and along streets are typically grown to large size in nurseries before being transplanted to their final growing sites. According to tendering rules within the European Union (EU), any business may compete for public contracts in any EU country, and this applies to purchases of valuable lots of nursery trees. There is however a risk of poor transplanting success if the trees are imported from very distant locations with a different pace of spring development. The aim of this study was to implement a Thermal Time model to predict the spring development of Tilia trees to find out in which geographical area the spring development is sufficiently similar to conditions in southern Finland, so that the success of transplantation of the trees is not unduly risked. We used phenological observations collected at the International Phenological Gardens (IPGs) over the whole of Europe, together with ERA-Interim weather data to estimate the model parameters, and then used the same date to predict the onset of leaf unfolding ofTilia during the years 1980 to 2015. Producing maps of phenological development of Tilia, we concluded that there are no large risks of frost damage if tree import area is limited to northern parts of Baltics or to the west coast of Scandinavia.

Trade-offs among transcription elongation rate, number, and duration of ubiquitous pauses on highly transcribed bacterial genes

2021 ◽  
pp. 2150020
Author(s):  
Tomáš Gedeon ◽  
Lisa Davis ◽  
Katelyn Weber ◽  
Jennifer Thorenson
Keyword(s):  
Functional Relationship ◽  
Surrounding Medium ◽  
Elongation Rate ◽  
Model Parameters ◽  
Transcription Rate ◽  
Initiation Rate ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
Trade Offs ◽  
Elongation Process

In this paper, we study the limitations imposed on the transcription process by the presence of short ubiquitous pauses and crowding. These effects are especially pronounced in highly transcribed genes such as ribosomal genes (rrn) in fast growing bacteria. Our model indicates that the quantity and duration of pauses reported for protein-coding genes is incompatible with the average elongation rate observed in rrn genes. When maximal elongation rate is high, pause-induced traffic jams occur, increasing promoter occlusion, thereby lowering the initiation rate. This lowers average transcription rate and increases average transcription time. Increasing maximal elongation rate in the model is insufficient to match the experimentally observed average elongation rate in rrn genes. This suggests that there may be rrn-specific modifications to RNAP, which then experience fewer pauses, or pauses of shorter duration than those in protein-coding genes. We identify model parameter triples (maximal elongation rate, mean pause duration time, number of pauses) which are compatible with experimentally observed elongation rates. Average transcription time and average transcription rate are the model outputs investigated as proxies for cell fitness. These fitness functions are optimized for different parameter choices, opening up a possibility of differential control of these aspects of the elongation process, with potential evolutionary consequences. As an example, a gene’s average transcription time may be crucial to fitness when the surrounding medium is prone to abrupt changes. This paper demonstrates that a functional relationship among the model parameters can be estimated using a standard statistical analysis, and this functional relationship describes the various trade-offs that must be made in order for the gene to control the elongation process and achieve a desired average transcription time. It also demonstrates the robustness of the system when a range of maximal elongation rates can be balanced with transcriptional pause data in order to maintain a desired fitness.

Internal magnetic field tests and magnetic field coupling model of a three-coil magnetorheological damper

2020 ◽  
Vol 31 (19) ◽  
pp. 2179-2195 ◽  
Author(s):  
Yang Yang ◽  
Zhao-Dong Xu ◽  
Ying-Qing Guo ◽  
Yan-Wei Xu ◽  
Jie Zhang
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Field Tests ◽  
Coupling Model ◽  
Magnetorheological Damper ◽  
Internal Magnetic Field ◽  
Magnetorheological Dampers ◽  
Element Analysis ◽  
Field Coupling ◽  
Magnetic Field Coupling

Magnetorheological damper is a typical semi-active control device. Its output damping force varies with the internal magnetic field, which is a key factor affecting the dynamic performance of the magnetorheological dampers. Existing studies about the magnetic field of magnetorheological dampers are limited to theoretical analysis; thus, this study aims to experimentally explore the complicated magnetic field distribution inside the magnetorheological dampers with multiple coils. First, the magnetic circuit of a three-coil magnetorheological damper was theoretically analyzed and designed, and the finite element model of the three-coil magnetorheological damper was set up to calculate the magnetic induction intensities of the damping gaps in different currents and numbers of coil turns. A three-coil magnetorheological damper embedded with a Hall sensor was then manufactured based on the theoretical and finite element analysis, and internal magnetic field tests under different conditions were carried out to obtain the actual magnetic induction intensities. At last, the magnetic field coupling model of the three-coil magnetorheological damper was proposed by introducing a coupling coefficient to describe the complex magnetic field distribution due to the strong coupling effect of the three coils, and the results calculated by the proposed model agreed well with the finite element analysis and magnetic field test data. The proposed model lays a foundation for the optimal design of the magnetic circuit and the mathematical model of multi-coil magnetorheological dampers.

Sign in / Sign up

Export Citation Format

Share Document