A New Hybrid Friction Damper (HFD) for Dual-Level Performance of Steel Structures

2021 ◽  
Author(s):  
Babak Shahbazi ◽  
Elham Moaddab
Keyword(s):  
Steel Structures ◽  
Friction Damper ◽  
Level Performance

Seismic retrofit of structures using rotational friction dampers with restoring force

2020 ◽  
Vol 23 (16) ◽  
pp. 3525-3540
Author(s):  
Asad Naeem ◽  
Jinkoo Kim
Keyword(s):  
Ground Motions ◽  
Design Procedure ◽  
Steel Structures ◽  
Friction Damper ◽  
Heavy Duty ◽  
Limit States ◽  
Restoring Force ◽  
Friction Dampers ◽  
Torsional Spring ◽  
Capacity Spectrum

In this study, the seismic performance of a rotational friction damper with restoring force is presented. The torsional spring friction damper consists of rotational friction pads with the heavy duty torsional springs attached on both sides of the friction damper. An analytical model and a design procedure for the damper are developed using capacity spectrum method. A parametric study is carried out to investigate the influence of the torsional spring in the response of the structure when subjected to ground motions. The seismic performances of steel structures retrofitted with the torsional spring friction damper and conventional rotational friction dampers are evaluated using fragility analysis, which shows that the structure retrofitted with the torsional spring friction damper has the smallest probability of reaching the specific limit states.

Simplified seismic code design procedure for friction-damped steel frames

1999 ◽  
Vol 26 (1) ◽  
pp. 55-71 ◽  
Author(s):  
Yaomin Fu ◽  
Sheldon Cherry
Keyword(s):  
Design Procedure ◽  
Steel Structures ◽  
Lateral Force ◽  
Building Codes ◽  
Degree Of Freedom ◽  
Friction Damper ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Damped System ◽  
Seismic Force

This paper describes the development of a proposed seismic design procedure for friction-damped steel structures, which employs the lateral force provisions used in many modern building codes. Closed-form expressions are first derived that relate the normalized response of a single degree of freedom friction-damped system with the system parameters, such as bracing stiffness ratio, damper slip ratio, and frame member ductility. A parametric analysis is then used to reveal that the seismic displacement of a friction-damped frame can be controlled by combining the frame stiffness with the bracing stiffness of the friction damper component, while the seismic force can be controlled by the damper slip force. A force modification factor (equivalent to the code R-factor) and displacement estimate for a friction-damped system are next determined. The single degree of freedom results are subsequently used to develop expressions for dealing with the multi degree of freedom situation, which permits the seismic lateral force design procedure adopted by many current building codes to be applied to friction-damped systems. The proposed procedure allows the frame response to be controlled so that the displacement can be limited to small magnitudes and the overall structural shape to an essentially straight-line deformation. Design examples illustrate that friction-damped frame systems are economical and offer a better overall response performance than that provided by conventional systems under the design earthquake.Key words: passive energy dissipation system, friction damper, steel frame, design procedure, static analysis.

scholarly journals Mitigating the Steel Structures Using Friction Damper Device

2017 ◽  
Vol 14 (02) ◽  
pp. 85-92
Author(s):  
Dawood M ◽  
El-Hakem Y ◽  
Tork B ◽  
Mokhtar A
Keyword(s):  
Steel Structures ◽  
Friction Damper

scholarly journals A Combined Analytical Method for Intelligent Control of Friction Damped Structures

2021 ◽  
Vol 29 (4) ◽  
Author(s):  
Kamyar Gharra ◽  
Karen Khanlari ◽  
Jafar Asgari Marnani
Keyword(s):  
Control System ◽  
Intelligent Control ◽  
Analytical Method ◽  
Structural Engineering ◽  
Control Level ◽  
Steel Structures ◽  
Matrix Analysis ◽  
Friction Damper ◽  
Intelligent Control System ◽  
Processing Module

Controlling structures and increasing the prognosis of their behaviour before natural disasters are the most critical issues in structural engineering. To that end, predicting the destructive effects of earthquakes on both acceleration and displacement of structures would be beneficial. This paper suggests an intelligent control system that realises simultaneous control of acceleration and displacement parameters. There are two modules in the system. First, the preserving module aims to estimate the crisis thresholds of acceleration and displacement based on the historical seismic data of each area. Second, the processing module finds the optimum value of the slip load of the friction damper so that both acceleration and displacement are controlled. We introduce an analytical method based on a matrix analysis approach and heuristic algorithm (MAHA) as a core of the processing module. MAHA would analyse the structure response, and the friction damper would determine the optimum slip load. The numerical and software simulation results for various one-bay and two-bay steel structures show that the proposed intelligent control system applies to multiple frictions damped structures under different earthquake records. In addition, a control level of 80% in acceleration and displacement of structures is achieved compared to an uncontrolled state. Moreover, the mentioned system enables the engineers to find appropriate friction dampers during the design of structures.

Predicting Entry-Level Performance Using Facet-Level, Personality-Based Employability Scales

2012 ◽  
Author(s):  
Ashley E. J. Palmer ◽  
Lauren N. Robertson ◽  
Courtney A. Nelson ◽  
Dara R. Pickering
Keyword(s):  
Entry Level ◽  
Level Performance

Trait- Versus State-Level Performance on the MMPI-2 As Assessed by the Ruff Neurobehavioral Inventor

2013 ◽  
Author(s):  
Brandon Browne ◽  
Anthony P. Andrews ◽  
Jada Stewart ◽  
Charles J. Golden
Keyword(s):  
State Level ◽  
Level Performance

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

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