scholarly journals Review of Magnetorheological Damping Systems on a Seismic Building

2021 ◽  
Vol 11 (19) ◽  
pp. 9339
Author(s):  
Bhre Wangsa Lenggana ◽  
Ubaidillah Ubaidillah ◽  
Fitrian Imaduddin ◽  
Seung-Bok Choi ◽  
Yusep Muslih Purwana ◽  
...  
Keyword(s):  
Building Structures ◽  
Building Structure ◽  
Magnetorheological Dampers ◽  
Active System ◽  
Viscous Dampers ◽  
Tuned Mass Dampers ◽  
Bingham Model ◽  
Material Loss ◽  
Advantages And Disadvantages ◽  
Mr Dampers

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.

FORMATION OF FORTIFICATION ART IN ANCIENT EAST COUNTRIES

2019 ◽  
Vol 21 (4) ◽  
pp. 94-124
Author(s):  
Е. N. Polyakov ◽  
M. I. Korzh
Keyword(s):  
Ancient Egypt ◽  
Building Structures ◽  
Ancient China ◽  
Natural Landscape ◽  
Advantages And Disadvantages ◽  
Medieval China ◽  
The Status ◽  
Architectural Structures ◽  
The City ◽  
New Babylon

The article presents a comparative analysis of fortification art monuments in such East countries from Ancient Egypt to medieval China. An attempt is made to identify the main stages of the fortification development from a stand-alone fortress (citadel, fort) to the most complex systems of urban and border fortifications, including moats, walls and gates, battle towers. It is shown that the nature of these architectural structures is determined by the status of the city or settlement, its natural landscape, building structures and materials, the development of military and engineering art. The materials from poliorceticon (Greek: poliorketikon, poliorketika), illustrate the main types of siege machines and mechanisms. The advantages and disadvantages of boundary shafts and long walls (limes). The most striking examples are the defensive systems of Assyria, New Babylon, Judea and Ancient China.

Influence of viscous dampers ultimate capacity on the seismic reliability of building structures

2021 ◽  
Vol 91 ◽  
pp. 102096
Author(s):  
Fabrizio Scozzese ◽  
Laura Gioiella ◽  
Andrea Dall'Asta ◽  
Laura Ragni ◽  
Enrico Tubaldi
Keyword(s):  
Building Structures ◽  
Ultimate Capacity ◽  
Viscous Dampers ◽  
Seismic Reliability

Optimal tuned direct adaptive controller for seismic protecting of structures

2021 ◽  
pp. 1045389X2098878
Author(s):  
Amin Hosseini ◽  
Touraj Taghikhany ◽  
Milad Jahangiri
Keyword(s):  
Sensitivity Analysis ◽  
Adaptive Control ◽  
Optimization Problem ◽  
Adaptive Controller ◽  
Sensitivity Analyses ◽  
Building Structures ◽  
Building Structure ◽  
The Past ◽  
Innovative Method ◽  
Story Building

In the past few years, many studies have proved the efficiency of Simple Adaptive Control (SAC) in mitigating earthquakes’ damages to building structures. Nevertheless, the weighting matrices of this controller should be selected after a large number of sensitivity analyses. This step is time-consuming and it will not necessarily yield a controller with optimum performance. In the current study, an innovative method is introduced to tuning the SAC’s weighting matrices, which dispenses with excessive sensitivity analysis. In this regard, we try to define an optimization problem using intelligent evolutionary algorithm and utilized control indices in an objective function. The efficiency of the introduced method is investigated in 6-story building structure equipped with magnetorheological dampers under different seismic actions with and without uncertainty in the model of the proposed structure. The results indicate that the controller designed by the introduced method has a desirable performance under different conditions of uncertainty in the model. Furthermore, it improves the seismic performance of structure as compared to controllers designed through sensitivity analysis.

Semi-Active Damping of Ground Resonance in Helicopters Using Magnetorheological Dampers

2000 ◽  
Author(s):  
Norman M. Wereley ◽  
Nicolas Costes
Keyword(s):  
Mr Damper ◽  
Active Damping ◽  
Rotor System ◽  
Magnetorheological Dampers ◽  
Resonance Analysis ◽  
Mr Dampers ◽  
Resonance Behavior ◽  
Ground Resonance ◽  
And Control

Abstract We will assess the capabilities of physically motivated MR dampers to mitigate ground resonance instability and control the damping level of rotor lag modes. The objectives of this research are threefold: (1) develop a methodology for the integration of the MR damper into a classic linear ground resonance analysis assuming an isotropic rotor hub (all dampers and blades similar) and an anisotropic rotor hub (due to lag damper dissimilarity due to damage, for example), (2) assess whether MR dampers can stabilize a rotor system that exhibits unstable ground resonance, (3) assess whether MR dampers can stabilize a rotor which exhibits unstable ground resonance behavior due to lag damper degradation or damage. The analyses developed in this study show that MR dampers are feasible for achieving these goals.

scholarly journals Desert Habitation History by 14C Dating of Soil Layers in Rural Building Structures (Negev, Israel): Preliminary Results from Horvat Haluqim

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 391-406 ◽  
Author(s):  
Hendrik J Bruins ◽  
Johannes van der Plicht ◽  
Mordechai Haiman
Keyword(s):  
Material Culture ◽  
Iron Age ◽  
Negev Desert ◽  
Building Structures ◽  
Building Structure ◽  
Relative Probability ◽  
14C Dating ◽  
Undisturbed Soil ◽  
Preliminary Results ◽  
Human Habitation

Traditional archaeological approaches in the central Negev Desert used to employ excavation techniques in post-prehistoric periods in which stratigraphy is based on architecture, while material culture forms the basis for dating assessment and chronology. Such an approach was understandable, as it focused on the most visible remains of past human habitation. However, the detailed habitation record is in the soil rather than in the walls. Moreover, ceramics and stone tools in desert cultures often have limited time resolution in terms of absolute chronology. The rural desert site of Horvat Haluqim in the central Negev yielded 2 habitation periods with the traditional methodology: (1) Roman period, 2nd–3rd centuries CE; (2) Iron Age IIA, 10th century BCE. We have conducted at Horvat Haluqim initial excavations in small building remains that were never excavated before. Our excavation methodology focuses on detailed examination of the archaeological soil in building structures, coupled with accelerator mass spectrometry (AMS) radiocarbon dating for chronology, and micromorphology of undisturbed soil samples to study stratigraphy and soil contents at the microscopic scale. Here, we report preliminary results, concentrating on the 14C dates. These suggest a much longer habitation history at the site during the Iron Age. The 14C dates obtained so far from these building remains cover Iron Age I, II, III, and the Persian period. The oldest calibrated date (charred C4 plants) in a rectangular building structure (L100) is 1129–971 BCE (60.5%, highest relative probability). The youngest calibrated date in a round building structure (L700) is 540–411 BCE (57.9%, highest relative probability). This excavation methodology provides additional “eyes” to look at past human habitation in the Negev Desert, seeing more periods and more detail than was possible with traditional schemes and ceramic dating.

Dynamic Models for Magnetorheological Dampers and its Feedback Linearization

2009 ◽  
Vol 79-82 ◽  
pp. 1205-1208 ◽  
Author(s):  
Cheng Zhang ◽  
Lin Xiang Wang
Keyword(s):  
Differential Equation ◽  
Phase Transition ◽  
Ordinary Differential Equation ◽  
Feedback Linearization ◽  
Dynamic Models ◽  
Nonlinear Ordinary Differential Equation ◽  
Transition Theory ◽  
Magnetorheological Dampers ◽  
Differential Model ◽  
Mr Dampers

In the current paper, the hysteretic dynamics of magnetorheological dampers is modeled by a differential model. The differential model is constructed on the basis of a phenomenological phase transition theory. The model is expressed as a second order nonlinear ordinary differential equation with bifurcations embedded in. Due to the differential nature of the model, the hysteretic dynamics of the MR dampers can be linearized and controlled by introducing a feedback linearization strategy.

Numerical Simulation of Building Strength when Foundation Subsides Unevenly

2012 ◽  
Vol 588-589 ◽  
pp. 2069-2073
Author(s):  
Jing Ma ◽  
Jun Zhao ◽  
Yu Ling Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Building Structures ◽  
Building Structure ◽  
Element Method

A building structure is analyzed using finite element method. The stresses and strains of the structure are calculated numerically, when the foundation subsides unevenly. Thus, the effect of the sedimentation is evaluated. The results can be referenced in the evaluation of building structures.

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