scholarly journals Seismic Design of Bolted Connections in Steel Structures—A Critical Assessment of Practice and Research

Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Tiago Ribeiro ◽  
Luís Bernardo ◽  
Ricardo Carrazedo ◽  
Dario De Domenico
Keyword(s):  
Earthquake Engineering ◽  
System Analysis ◽  
Steel Structures ◽  
Design Codes ◽  
Braced Frames ◽  
Structural Behaviour ◽  
Design Rules ◽  
Steel Connections ◽  
The Cost ◽  
Local Connection

The importance of connections in steel structures is paramount, not only because it greatly influences the cost of construction and provides room for innovations, but also due to the connections’ impact on global structural behaviour. Therefore, research into innovative connections for seismic applications and related design criteria has significantly grown in recent years. However, it has been pursued mostly on local—connection or frame—levels, leaving the system analysis and code compliance levels with a meagre investigation. Moreover, less than 1% of published papers concerning steel connections and earthquake engineering are review articles. To overcome this gap, this systematic review of more than 240 references, including scientific contributions and design codes in the field aimed to cover both recent research and current shortcomings in practice and regulations. It has been found that European design rules updated to a fully performance-based design philosophy is imminent and is deemed to bring pre-qualified joints and increased complexity. Design rules have been systematized, and current hindrances have been highlighted. A deeper look into research needs and trends showed that investigations in connections for concentrically X braced frames are still a necessity, while developments in self-centring and replaceable connections as well as in simple solutions for increasing damping are expected to modify how joints are designed, as soon as semi-rigid and partial strength connections are more easily allowed by design codes.

Experimental characterization of quick mechanical connecting systems for cold-formed steel structures

2016 ◽  
Vol 20 (7) ◽  
pp. 1098-1110 ◽  
Author(s):  
Luigi Fiorino ◽  
Vincenzo Macillo ◽  
Raffaele Landolfo
Keyword(s):  
Shear Walls ◽  
Steel Structures ◽  
Structural Behaviour ◽  
Modular Systems ◽  
Cyclic Shear ◽  
Steel Connections ◽  
Modular Units ◽  
Cold Formed Steel ◽  
Strength And Stiffness ◽  
Reliable Solution

Among the several available building systems, constructions involving cold-formed steel profiles represent an efficient and reliable solution. These systems are very suitable to be used in pre-fabricated modular constructions, thanks to their lightness and possibility to automate the building process. In these systems, connections are usually made with self-tapping screws and play a key role both in fabrication, for reducing assembling times of modular units, and in structural behaviour, particularly for sheathing-braced solutions. In a framework of the European project ELISSA (Energy Efficient LIghtweight-Sustainable-SAfe-Steel Construction), which was devoted to the development and demonstration of cold-formed steel modular systems, an experimental campaign on quick connecting systems alternative to screws was carried out. This article shows the results of this experimental activity, consisting of monotonic and cyclic shear tests on connection systems. In particular, the tested specimens are clinching for steel-to-steel connections, whereas the fasteners used for panel-to-steel connections of walls and floors are ballistic nails. Tests results provided important information on the shear response of the connections with particular reference to the values of strength and stiffness, which are the main parameters for developing the seismic design of sheathed shear walls.

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.

scholarly journals Fast 10-Point DFT Algorithm for Power System Harmonic Analysis

2021 ◽  
Vol 11 (15) ◽  
pp. 7007
Author(s):  
Janusz P. Paplinski ◽  
Aleksandr Cariow
Keyword(s):  
Computational Complexity ◽  
Power System ◽  
Harmonic Analysis ◽  
Efficient Algorithm ◽  
System Analysis ◽  
Spectral Leakage ◽  
Power System Analysis ◽  
Improve Accuracy ◽  
The Cost ◽  
Harmonic Power

This article presents an efficient algorithm for computing a 10-point DFT. The proposed algorithm reduces the number of multiplications at the cost of a slight increase in the number of additions in comparison with the known algorithms. Using a 10-point DFT for harmonic power system analysis can improve accuracy and reduce errors caused by spectral leakage. This paper compares the computational complexity for an L×10M-point DFT with a 2M-point DFT.

Earthquake Performance Analysis of Steel Structures with A3 Plan Irregularities

2021 ◽  
Vol 10 (12) ◽  
pp. 174-179
Author(s):  
Özlem Çavdar
Keyword(s):  
Earthquake Engineering ◽  
Design Method ◽  
Steel Structures ◽  
Nonlinear Static Analysis ◽  
Seismic Performance Evaluation ◽  
Moment Resisting Frame ◽  
Earthquake Effect ◽  
Steel Building ◽  
Moment Resisting ◽  
Earthquake Performance

In earthquake engineering, a performance-based design method is used to determine the level of the expected performance of the structures under the earthquake effect. The level of performance is related to the damage situation that could be occurred in the structure after the earthquake. In the performance-based structural design, it is predicted that more than one damage levels emerge under one certain earthquake effect. In this study, the seismic behavior of steel structures with plan irregularities in the Turkey Building Earthquake Code in the 2018 (TBEC-2018) is investigated by the nonlinear static analysis methods. The selected steel structures are located in İzmir, Turkey. The Turkey Earthquake Code in 2018 is considered for assessing seismic performance evaluation of the selected moment-resisting frame steel building. Four different A3 type irregularity was investigated. The steel building with no irregularity in its plan. was selected as the structure of the reference. The performance goals of the five different steel structures are evaluated by applying the pushover and procedures of the TBEC-2018. The steel structures were compared by obtaining pushover curves for both the X and Y directions. The results show that the effects of A3 type irregularity should be not considered in design and buildings without irregularities are safer.

Solar Concentrating Systems Using Small Mirror Arrays

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Joachim Göttsche ◽  
Bernhard Hoffschmidt ◽  
Stefan Schmitz ◽  
Markus Sauerborn ◽  
Reiner Buck ◽  
...  
Keyword(s):  
Power Plants ◽  
Raw Materials ◽  
Large Fraction ◽  
Steel Structure ◽  
Steel Structures ◽  
Cost Effective ◽  
Wind Loads ◽  
Drive Systems ◽  
Mirror Area ◽  
The Cost

The cost of solar tower power plants is dominated by the heliostat field making up roughly 50% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ∼20 kg/m2 steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m2 caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10×10 cm2) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0.5×0.5 m2 demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun’s path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.

Application of Fracture Mechanics to Steel Connections in Moment Frames under Seismic Loading

1997 ◽  
Vol 1 (1) ◽  
pp. 23-37 ◽  
Author(s):  
C. Joh ◽  
W.F. Chen
Keyword(s):  
Fracture Mechanics ◽  
Steel Structures ◽  
Northridge Earthquake ◽  
Moment Frames ◽  
Moment Connections ◽  
Related Factors ◽  
Steel Connections ◽  
Moment Connection ◽  
San Fernando ◽  
The Moment

The 6.8 magnitude Northridge earthquake that shook California's San Fernando Valley on January 17 in 1994, did not cause the collapse of any steel structures but connections, confidently designed and constructed in the past with traditional code simplification and common site welding techniques, were discovered not to meet our expectations. This paper reviews connection failures during the 1994 Northridge earthquake and the design philosophy and examines the post-Northridge earthquake experimental and analytical researches. Possible causes of the moment connections damage are categorized into three classes; welding-related factors, design-related factors, and material-related factors. For the analyses, the idealizations of the moment connection considering each factor are studied. From the idealization of the moment connection, the five-plate model is analyzed to investigate the stress concentration and stress state of the connection. The equivalent design crack models are investigated using the fracture mechanics approach.

TRENDS IN THE DEVELOPMENT OF REACTIVE FIRE PROTECTION (LITERATURE REVIEW)

2021 ◽  
pp. 75-90
Author(s):  
Lyubov Vakhitova ◽  
◽  
Nadiya Taran ◽  
Konstantin Kalafat ◽  
◽  
...  
Keyword(s):  
Literature Review ◽  
Fire Protection ◽  
Flame Retardants ◽  
Practical Importance ◽  
Fire Retardant ◽  
Steel Structures ◽  
Life Time ◽  
Practical Significance ◽  
Protection Measures ◽  
The Cost

Purpose. Identification of the main directions of evolution of scientific researches concerning development and improvement of fire protective reactive coatings of intumescent type for steel constructions. Methods. Analysis of literature sources, study and generalization of information, classification and modeling of chemical processes. Results. As a result of the performed researches it has been shown that of all the developed reactive fire protection systems for increasing the fire resistance of steel structures the intumescent composition of ammonium polyphosphate/ pentaerythritol / melamine / polymer is the most widespread and economically justified. To reduce the cost of fire protection measures, it is necessary to improve the coatings of the intumescent type in the following main areas: increasing of fire protection efficiency with a decrease in the thickness of the fire protection layer; prolongation of life time with strengthening of resistance to external factors; reducing the cost of the prescription composition of intumescent paint due to the use of nanomaterials. Scientific novelty. It has been established that nanoclays, nanooxides of metals and silicon, LDH compounds and their analogues should be considered the most promising and multifunctional. The presence of nanomaterials in intumescent compositions allows to increase the environmental parameters of fire-retardant treatment due to the rejection of halogen flame retardants, boron compounds, formaldehyde resins. In addition, the presence of nanocompounds in intumescent coatings significantly reduces smoke in fire. Practical significance. The conclusions obtained from the literature review are of practical importance for the development of new approaches to the design of fire-fighting materials with improved performance through the use of nanomaterials, which provides a strong fire retardant foam char layer and provides rigidity of the insulation frame.

Some Noteworthy Aspects in Designing High-Speed PCB

2013 ◽  
Vol 662 ◽  
pp. 846-850
Author(s):  
Jiang Hong ◽  
Zhi Wei Tang ◽  
Long Hu Chen
Keyword(s):  
System Design ◽  
Integrated Circuit ◽  
High Speed ◽  
Electromagnetic Compatibility ◽  
Signal Integrity ◽  
Design Rules ◽  
Pcb Design ◽  
Key Factor ◽  
Switch Rate ◽  
The Cost

With the increase of integrated circuit switch rate and PCB density, signal integrity has become one of the problems must be concerned in high-speed PCB design. How to fully consider EMC (Electromagnetic compatibility) and take effective measures has been a key factor of a system design. Based on the consideration of EMC, the author put forward some aspects in designing high-speed PCB. The optimized PCB design rules have steady and credible performance, the development period is shortened and the cost is reduced. The conclusions drawn from the dissertation are helpful to the design of high-speed PCB.

scholarly journals Review on Cold-Formed Steel Connections

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yeong Huei Lee ◽  
Cher Siang Tan ◽  
Shahrin Mohammad ◽  
Mahmood Md Tahir ◽  
Poi Ngian Shek
Keyword(s):  
Structural Characteristics ◽  
Steel Structures ◽  
Rolled Steel ◽  
Steel Connections ◽  
Steel Framing ◽  
Steel Sections ◽  
Cold Formed Steel ◽  
Hot Rolled ◽  
Hot Rolled Steel ◽  
Review Current

The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

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