Seismic Design and Hybrid Tests of a Full-Scale Three-Story Concentrically Braced Frame using In-Plane Buckling Braces

2013 ◽  
Vol 29 (3) ◽  
pp. 1043-1067 ◽  
Author(s):  
Ching-Yi Tsai ◽  
Keh-Chyuan Tsai ◽  
Pao-Chun Lin ◽  
Wai-Hang Ao ◽  
Charles W. Roeder ◽  
...  
Keyword(s):  
Seismic Design ◽  
Axial Strain ◽  
Local Buckling ◽  
Full Scale ◽  
Dynamic Tests ◽  
Braced Frame ◽  
Concentrically Braced Frame ◽  
Nonlinear Responses ◽  
Highly Nonlinear ◽  
Concentrically Braced

This research investigates the brace-to-gusset connection designs to allow the braces buckle in the plane (IP) of the frame. In order to study the performance of the IP buckling brace connections with different design details, five 3,026 mm–long A36 H 175 × 175 × 7.5 × 11 mm braces were tested using cyclically increasing axial displacements. All specimens failed at an average axial strain less than 0.025 due to the brace fracture at the mid-length where severe local buckling had occurred. Pseudo-dynamic tests on a three-story special concentrically braced frame (SCBF) using the proposed brace end connection details for six A36 H 150 × 150 × 7 × 10 mm braces were conducted using the PGA = 597 cm/s2 LA03 record to confirm with the component tests. The knife plates and IP buckling braces sustained a peak 0.049 rad interstory drift under the design base earthquake without fracture. The highly nonlinear responses were satisfactorily predicted by OpenSees. Recommendations on the seismic design of the IP buckling brace connections are provided.

Test of a Full Scale Concentrically Braced Frame with Multi-Story X-Bracing

2008 ◽  
Author(s):  
Jake Powell ◽  
Kelly Clark ◽  
Keh-Chyuan Tsai ◽  
Charles Roeder ◽  
Dawn Lehman
Keyword(s):  
Full Scale ◽  
Braced Frame ◽  
Concentrically Braced Frame ◽  
Concentrically Braced

Seismic evaluation of single-storey steel buildings

1999 ◽  
Vol 26 (4) ◽  
pp. 379-394 ◽  
Author(s):  
M S Medhekar ◽  
DJL Kennedy
Keyword(s):  
Seismic Performance ◽  
Response Spectrum ◽  
Time History ◽  
Analytical Models ◽  
Steel Buildings ◽  
Concentrically Braced Frames ◽  
Braced Frame ◽  
Seismic Zones ◽  
Concentrically Braced Frame ◽  
Concentrically Braced

The seismic performance of single-storey steel buildings, with concentrically braced frames and a roof diaphragm that acts structurally, is evaluated. The buildings are designed in accordance with the National Building Code of Canada 1995 and CSA Standard S16.1-94 for five seismic zones in western Canada with seismicities ranging from low to high. Only frames designed with a force modification factor of 1.5 are considered. Analytical models of the building are developed, which consider the nonlinear seismic behaviour of the concentrically braced frame, the strength and stiffness contributions of the cladding, and the flexibility, strength, and distributed mass of the roof diaphragm. The seismic response of the models is assessed by means of a linear static analysis, a response spectrum analysis, a nonlinear static or "pushover" analysis, and nonlinear dynamic time history analyses. The results indicate that current design procedures provide a reasonable estimate of the drift and brace ductility demand, but do not ensure that yielding is restricted to the braces. Moreover, in moderate and high seismic zones, the roof diaphragm responds inelastically and brace connections are overloaded. Recommendations are made to improve the seismic performance of such buildings.Key words: analyses, concentrically braced frame, dynamic, earthquake, flexible diaphragm, low-rise, nonlinear, seismic design, steel.

Floor Spectra Estimates for an Industrial Special Concentrically Braced Frame Structure

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Roberto Javier Merino Vela ◽  
Emanuele Brunesi ◽  
Roberto Nascimbene
Keyword(s):  
Time History ◽  
Response Spectra ◽  
Frame Structure ◽  
Eurocode 8 ◽  
Industrial Complex ◽  
Braced Frame ◽  
Nonstructural Components ◽  
Floor Response Spectra ◽  
Concentrically Braced Frame ◽  
Concentrically Braced

Nonstructural components play an important role in the correct functioning of industrial facilities, which may suffer greatly from earthquake-induced actions, as demonstrated by past seismic events. Therefore, the correct evaluation of seismic demands acting upon them is of utmost importance when assessing or designing an industrial complex exposed to seismic hazard. Among others, nonlinear time history analyses (NLTHA) of structural systems including nonstructural elements and floor response spectra are well-known methods for computing these actions, the former being more accurate and the latter being less onerous. This work focuses on deriving floor spectra for a steel special concentrically braced frame (SCBF), which is a common type of lateral-load resisting system for industrial frames. The results are used to compute the seismic actions on a small liquid storage tank mounted on the case study frame. Additionally, the results are compared to those obtained by modeling the structure and the tank together, that is, by modeling the tank explicitly and incorporating it within the model of the support structure. To this end, a simple model, consisting of two uncoupled single degree-of-freedom systems, is used for the tank. The floor spectra resulting from both approaches are compared to establish differences in the behavior of the structure and nonstructural element/component. Finally, the seismic demand on the tank—obtained by direct and indirect analyses—is compared to that obtained by applying ASCE 7-10 and Eurocode 8 prescriptions.

Code provisions for seismic design for concentrically braced steel frames

1992 ◽  
Vol 19 (6) ◽  
pp. 1025-1031 ◽  
Author(s):  
R. G. Redwood ◽  
A. K. Jain
Keyword(s):  
Seismic Design ◽  
Structural Engineering ◽  
Steel Frames ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
Braced Frame ◽  
Concentrically Braced ◽  
Interstorey Drift ◽  
Available Information ◽  
Steel Braced Frame

Extensive research into the inelastic seismic response of concentrically braced frames and their components has been carried out in the last two decades. This knowledge has now been incorporated into seismic design practice in several countries, notably the U.S.A., Canada, and New Zealand. In this paper, design specifications from these three countries, which derive largely from the same body of research, are compared. The basic design philosophy for concentrically braced steel frames, loading, and member detailing are examined. It is concluded that, in general, the Canadian specifications are in conformity with the available information and have many similar features to codes of the other countries. Significant differences exist in the classification of braced frames, between interstorey drift requirements, in the treatment of dual structural systems, and to a lesser extent in member detailing requirements. Some features of Canadian codes meriting review are identified. Key words: structural engineering, earthquakes, standards, steel, braced frame, ductility, concentric bracing, dual system.

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