scholarly journals Modelling Magnetorheological Dampers in Preyield and Postyield Regions

2019 ◽  
Vol 2019 ◽  
pp. 1-23 ◽  
Author(s):  
E. Palomares ◽  
A. L. Morales ◽  
A. J. Nieto ◽  
J. M. Chicharro ◽  
P. Pintado
Keyword(s):  
Experimental Tests ◽  
Magnetorheological Damper ◽  
Semiactive Control ◽  
Nonlinear Behaviour ◽  
Magnetorheological Dampers ◽  
Huge Number ◽  
Low Velocity ◽  
Highly Nonlinear ◽  
Control Schemes

The use of magnetorheological dampers has rapidly spread to many engineering applications, especially those related to transportation and civil engineering. The problem arises upon modelling their highly nonlinear behaviour: in spite of the huge number of apparently accurate models in the literature, most fail when considering the overall magnetomechanical behaviour. In this study, a brief but broad review of different magnetorheological damper models has been carried out, which includes characterisation, modelling, and comparison. Unlike many other studies, the analyses cover the behaviour from preyield to postyield regions of the MR fluid. The performance of the different models has been assessed by means of numerous experimental tests and by means of simulations in a simple and straightforward semiactive control case study. The results obtained prove that most models usually fail in predicting accurate low-velocity behaviour (before iron chains yield) and, as a result, may lead to bad estimations when used in control schemes due to modelling errors and chattering.

Development and simulation of magnetorheological damper for segment erector vibration control

2019 ◽  
Vol 43 (2) ◽  
pp. 237-247 ◽  
Author(s):  
Bo Yang ◽  
Ao Zhang ◽  
Yan Bai ◽  
Kuo Zhang ◽  
He Li
Keyword(s):  
Performance Enhancement ◽  
Fuzzy Controller ◽  
Random Excitation ◽  
Magnetorheological Damper ◽  
Magnetorheological Dampers ◽  
Linear Control Theory ◽  
Nonlinear Design ◽  
Highly Nonlinear ◽  
Takagi Sugeno ◽  
Segment Erector

In this paper, magnetorheological dampers are applied to a segment erector to replace passive vibration dampers. Because magnetorheological damper dynamics are highly nonlinear, design of a direct control system is impossible. To apply linear control theory directly to design the magnetorheological damper controller, the Takagi–Sugeno fuzzy model analytically represents the segment erector model. In addition, a disturbance observer based on a Takagi–Sugeno fuzzy controller is proposed for this system. Both simulations and experiments validate the performance enhancement and stability of the controller. The results show that the acceleration of the segment erector was reduced by 59.6% and 32.1% in oblique wave excitation and random excitation, respectively, compared to a conventional passive damper. The proposed fuzzy controller and magnetorheological dampers have great potential in practical applications because they can significantly improve the performance of a segment erector.

Cost-effective multi-objective optimal positioning of magnetorheological dampers and active actuators in large nonlinear structures

2016 ◽  
Vol 28 (2) ◽  
pp. 230-253 ◽  
Author(s):  
Mohsen Askari ◽  
Jianchun Li ◽  
Bijan Samali
Keyword(s):  
Control System ◽  
Active Control ◽  
Cost Effective ◽  
Optimal Number ◽  
Dynamic Responses ◽  
Nonlinear Behaviour ◽  
Magnetorheological Dampers ◽  
Multi Objective ◽  
Highly Nonlinear ◽  
Control Devices

The optimal number and location of control devices not only play a major role in an effective structural control system but also lead to a cost-effective design. This article presents a multi-objective optimization method based on a new genetic algorithm for simultaneous finding of the optimal number and placement of actuators and magnetorheological dampers, in active and semi-active vibration control of structures. The proposed strategy considers three objective functions to be minimized through optimization, including peak inter-storey drift ratio, peak acceleration and peak base shear force to make sure both human comfort and safety of the structure are guaranteed. Also, by choosing a pre-defined level of performance on dynamic responses of a structure, the designer can decide on decreasing or increasing the number of control devices in a systematic way and minimize the control cost. The approach is then validated through a nonlinear 20-storey benchmark problem. The results from active control system show how a problem that was initially solved with 25 actuators can be solved with less than a quarter of those actuators, having similar results in terms of aforementioned indices. The optimal distribution of different numbers of magnetorheological dampers in the same benchmark building is also studied in this article and compared to those obtained from actuators. Due to highly nonlinear behaviour of these devices, and also the complexity of the under-study benchmark structure, few reported researches have been conducted in this area. Also, the comparison between optimal places of active and semi-active control devices in the same structure has hitherto not been reported in the open literature.

An elastic phenomenological material law of technical textile with a nonlinear shear behaviour

2021 ◽  
pp. 073168442110058
Author(s):  
Dániel T Karádi ◽  
András A Sipos ◽  
Marianna Halász ◽  
Viktor Hliva ◽  
Dezső Hegyi
Keyword(s):  
Service Level ◽  
Shear Behaviour ◽  
Nonlinear Behaviour ◽  
Exponential Functions ◽  
Normal Stiffness ◽  
Material Parameters ◽  
Fitting Method ◽  
Highly Nonlinear ◽  
Nonlinear Shear ◽  
Magnitude Difference

In technical textile engineering, macro-level phenomenological modelling effectively describes the material’s highly nonlinear behaviour. However, existing material laws concentrate on the normal stiffness in the orthotropic yarns and simplify the shear effect because of the two orders of magnitude difference between shear and normal stiffness. This article introduces an improved phenomenological model that includes nonlinear shear behaviour, and it determines the material parameters with a previously applied data fitting method for exponential functions. The nonlinear shear behaviour is valid for the elastic state, that is, at the service level of the loads. Time-dependent, cyclic loading or plastic behaviour is not considered.

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.

scholarly journals SMART SECURITY AND SAFETY INDEX MEASUREMENT: A CASE STUDY IN BANDUNG INDONESIA

2019 ◽  
Vol 7 (5) ◽  
pp. 141-149
Author(s):  
Indrawati ◽  
Tania Dayarani ◽  
Husni Amani
Keyword(s):  
Mixed Method ◽  
Smart City ◽  
Safety Index ◽  
Huge Number ◽  
Safety Level ◽  
Index Measurement ◽  
The World ◽  
Index Level ◽  
The City

Purpose: Nowadays, the development of technology is very fast and increasingly sophisticated; no doubt all the problems in a city can be solved quickly and well. Hence, facing a huge number of the urban population, the city must adopt the strategy of smart city so that the standard of life can be improved. Some of the cities in the world have applied the concept of smart city. One of the dimensions in smart city concept is smart security and safety. This study aims to know the indicators and index level of smart security and safety in Bandung city of Indonesia. This research explores the indicators and measures the index level of smart security and safety in Bandung.  Methodology: The research method characteristics applied in this study is the exploratory sequential mixed method. Main Findings: This study finds that there are 20 indicators to measure the index level of smart security and safety. The smart security and safety level of Bandung city is 72% which is considered that on average the measured indicators are already good enough and satisfied, but there are some indicators that should be improved. The variable that should be improved is variable of Awareness and Understanding which has score of 49%. Implications/Applications: It is suggested by this study that the socialization of smart security and safety program such as Panic Button Application, LAPOR! The website should be more effective through making socialization more targeted and real.

Design of Fazl-Tash novel method for sustainable resilient comprehensive supplier selection problem

Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hamed Fazlollahtabar ◽  
Navid Kazemitash
Keyword(s):  
Supplier Selection ◽  
Huge Number ◽  
Simple Method ◽  
Content Type ◽  
Novel Method ◽  
Rank And Select ◽  
The Cost ◽  
Supplier Selection Problem ◽  
Industrial Company

Purpose However, due to the huge number of studies and on the other hand to be new and creative, the represented models and methods – as the two main parts of this field – have been got more complicated, which consequently have been turned into unpractical research studies for the realistic situations. Therefore, the purpose of this study is the representation of a novel and simple method to deal with the aforementioned gap. Design/methodology/approach To this end, Fazl-Tash method have been proposed, in which a thorough and complete model including 114 criteria and a simple technique to rank and select the best supplier have been presented. Sustainability and resiliency are considered in collecting criteria effective on supplier selection. Findings The method was carried out in a case study in an industrial company. The efficiency of the proposed method is evaluated in comparison with other conventional approaches. Originality/value As selecting the supplier plays a crucial role to bring some important advantages for companies, such as coping with the cost and time problems and influencing the majority of contemporary markets’ requirements, in recent years, there have been representing more effective studies in the supplier selection literature.

Performance Evaluation for Related Techniques of the Proposed Environment Pollution Monitoring System for an Iraqi Case Study

2021 ◽  
Vol 3 (2) ◽  
pp. 11-18
Author(s):  
Taha E. Al-jarakh ◽  
Osama Abbas Hussein ◽  
Alaa Khamees Al-azzawi ◽  
Mahmood Farhan Mosleh
Keyword(s):  
Performance Evaluation ◽  
Monitoring System ◽  
Pollution Monitoring ◽  
System Level ◽  
Environment Pollution ◽  
Huge Number ◽  
Iot Platform ◽  
Main Challenge ◽  
Level Performance

The main challenge of this research is to scale the IoT platform aspects related to exchanging, processing, and archiving messages at the lowest cost compute-wise, through evaluating and selecting the most appropriate techniques that can be used in the design of the environment pollution monitoring system for a case study of Iraq. The entirety of the optimization process aims to provide a nation-wide community-oriented service via the scalable platform. The platform provides an intake for a huge number of sensing nodes. Compute-operations following the form of data analysis, aggregation, sensors’ monitoring for the five air pollutants (SO2, CO, O3, NO2, and PM), in addition to radioactive contamination. Thus system-level performance evaluation takes place on the major compute-intensive operations. Thus, proposals are made to optimize the performance in terms of reducing the scripts execution time and the size of data and messages transmitted and stored in the system.

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