Amplified Seismic Loads in Steel Moment Frames

2016 ◽  
Vol 847 ◽  
pp. 222-232
Author(s):  
Bora Aksar ◽  
Selcuk Dogru ◽  
Bulent Akbas ◽  
Jay Shen ◽  
Onur Seker ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Ground Motions ◽  
Time History ◽  
Load Level ◽  
Steel Buildings ◽  
Moment Frames ◽  
Axial Loads ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting

This study focuses on exploring the seismic axial loads for columns in steel moment resisting frames (SMRFs) under strong ground motions. For this purpose, the increases in axial loads are investigated at the maximum lateral load level and the corresponding lateral displacement. The results are presented in terms of maximum amplification factors (Ω0) of all frame columns under the selected ground motions and axial load-moment levels in columns. four typical steel moment resisting frames representing typical low, medium and high rise steel buildings are designed based on the seismic design requirement in ASCE 7-10 and AISC 341-10 . An ensemble of ground motions range from moderate to severe are selected to identify the seismic response of each frames. Two sets of ground motions corresponding to 10% and 2% probability of exceedance are used in nonlinear dynamic time history analyses.

Code-Oriented Methodology for the Seismic Design of Regular Steel Moment-Resisting Braced Frames

2014 ◽  
Vol 30 (4) ◽  
pp. 1683-1709 ◽  
Author(s):  
Edgar Tapia-Hernández ◽  
Arturo Tena-Colunga
Keyword(s):  
Seismic Design ◽  
Time History ◽  
Federal District ◽  
Design Parameters ◽  
Braced Frames ◽  
Steel Buildings ◽  
Moment Frames ◽  
Concentrically Braced Frames ◽  
Design Spectrum ◽  
Moment Resisting

In order to help improve the seismic design of regular steel buildings structured with ductile moment-resisting concentrically braced frames (MRCBFs) using the general design methodology of Mexico's Federal District Code (MFDC-04), suitable design parameters were first assessed using the results of pushover analyses of 13 regular MRCBFs. In order to insure collapse mechanisms consistent with the assumptions implicit in a code-based design (strong-column/weak-beam/weaker-brace), it is proposed to relate the minimum strength ratio for the resisting columns of the moment frames and the bracing system. Improved equations are proposed for a more realistic assessment of ductility and overstrength factors. In a second stage, the effectiveness of the improved methodology was assessed with the design of six regular steel buildings with MRCBFs. Buildings were evaluated by performing both pushover and nonlinear time-history analyses under ten selected artificial ground motions related to the corresponding design spectrum.

A database of seismic designs, nonlinear models, and seismic responses for steel moment-resisting frame buildings

2020 ◽  
pp. 875529302097120
Author(s):  
Xingquan Guan M.EERI ◽  
Henry Burton M.EERI ◽  
Mehrdad Shokrabadi
Keyword(s):  
Nonlinear Models ◽  
Ground Motions ◽  
Structural Models ◽  
Service Level ◽  
Data Driven ◽  
Seismic Responses ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Nonlinear Structural ◽  
Moment Resisting

A number of simplified methodologies have been developed and used to estimate seismic drift demands in buildings. However, none of them have been systematically tested against a large number of buildings subjected to a diverse set of ground motions. This is partly attributed to the lack of existing databases of building designs, nonlinear structural models, and simulated seismic responses. This article introduces the development of a comprehensive database, which includes 621 special steel moment-resisting frames designed in accordance with modern codes and standards and their corresponding nonlinear structural models and seismic responses (i.e. peak story drifts, peak floor accelerations, and residual story drifts). The seismic responses for a subgroup of 100 steel moment-resisting frames subjected to three groups of site-specific ground motions (with 40 records each), at the service-level, design-based, and maximum considered earthquakes, are also included. The database has been utilized by the authors (in a separate study) to evaluate the performance of existing methods and develop data-driven and hybrid (combination of mechanics-based and data-driven) models for estimating seismic structural drift demands. The database can also be utilized in the development and implementation of a performance-based analytics-driven seismic design methodology.

Seismic fragility of steel moment-resisting frames in Vancouver and Montreal designed in the 1960s, 1980s, and 2010

2015 ◽  
Vol 42 (11) ◽  
pp. 919-929 ◽  
Author(s):  
Lucía Valentina Díaz Gómez ◽  
Oh-Sung Kwon ◽  
Mohammad Reza Dabirvaziri
Keyword(s):  
Numerical Models ◽  
Fragility Curves ◽  
Time History ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Nonlinear Time History Analyses ◽  
Moment Resisting ◽  
The 1960S ◽  
Steel Mrfs ◽  
Nonlinear Time History

Typical steel moment-resisting frames (MRF) of six-storey buildings in Vancouver and Montreal were designed for three different provisions of the National Building Code of Canada (1960s, 1980s, and 2010). Numerical models were developed in OpenSees to understand the seismic performance of the structures. These models accounted for strength and stiffness degradation through appropriate representations of the beam–column connection behaviours, which were calibrated against experimental results available in the literature. The behaviour of the buildings was evaluated through pushover and nonlinear time history analyses. The pushover analysis results showed that the 1960s and 2010 steel MRFs of both cities exhibited strong-column-weak-beam failure mode. The 1980s steel MRFs of both cities showed soft-storey mechanism. Fragility curves were developed for the steel MRFs based on the seismic demands evaluated using nonlinear time history analyses, which can be used for regional seismic impact assessment studies in the future.

Hysteresis Behavior of Square Tube Columns to H-Beam Connections with Vertical Stiffeners

2005 ◽  
Vol 8 (6) ◽  
pp. 561-572 ◽  
Author(s):  
Jinan Chung ◽  
Seongyon Seo ◽  
Chiaki Matsui ◽  
Sungmo Choi
Keyword(s):  
Test Methods ◽  
Test Results ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Steel Moment Resisting Frames ◽  
Simply Supported ◽  
Moment Resisting Frames ◽  
Connection Method ◽  
Moment Resisting ◽  
H Beam

This paper deals with confirming the usability of a new connection method for steel moment-resisting frames. The connections are strengthened with vertical stiffeners to connect square tube columns and H-shaped beams. Two test methods were selected with experimental parameters given as details. The first test is performed under symmetrical loading. Beams are simply supported on both ends and test load is applied to the top of the column. The second test is performed under anti-symmetric loading. The shape of test specimens is cruciform, with a beam and a column. The top end and base of the column are simply supported, and load is applied to both ends of the beam. Test results are summarized to investigate structural performances of the connection. Nonlinear FE analysis using ANSYS for moment-resisting frames was performed to confirm the test results. It was found that all specimens had sufficient capacities exceeding the full plastic strength of beam. Therefore, the connections strengthened with vertical stiffeners were successfully verified to have possibility as a new connection method for steel moment-frames.

scholarly journals Response of low-rise buildings to moderate ground shaking, particularly the May 1990 Weber earthquake

1994 ◽  
Vol 27 (3) ◽  
pp. 205-221
Author(s):  
S. Sritharan ◽  
D. J. Dowrick
Keyword(s):  
New Zealand ◽  
Seismic Performance ◽  
Ground Motions ◽  
Time History ◽  
Imperial Valley ◽  
Ground Shaking ◽  
Moment Resisting Frames ◽  
Moment Resisting ◽  
Spectral Accelerations

In the Weber earthquake of 13 May 1990 the stronger component of the ground motions recorded in Dannevirke was similar in strength to the El Centro S00E record from the 1940 Imperial Valley earthquake which underlies the New Zealand loadings code, The Modified Mercalli intensity in Dannevirke however was only about MM7 1⁄2, whereas the intensity corresponding to the 1984 earthquake code is about MM8 1⁄2 for the Dannevirke area. This paper compares the strength of the Dannevirke record in terms of spectral accelerations with (i) the above El Centro record, (ii) the Matahina dam record of the 1987 Edgecumbe earthquake, and (iii) the loadings of the 1984 and 1992 New Zealand codes. Also described in the paper are time-history analyses of one- and two- storey buildings subjected to the above ground motions in an attempt to explain why the damage levels were lower than might be expected from the strength of the recorded accelerograms. Comparisons are made of the seismic performance of moment-resisting frames and walled structures. Comments are made on two of the provisions of the 1992 loadings code.

scholarly journals Seismic Upgrading of Steel Moment-Resisting Frames by Means of Friction Devices

2014 ◽  
Vol 8 (1) ◽  
pp. 289-299 ◽  
Author(s):  
Esra Mete Güneyisi ◽  
Mario D'Aniello ◽  
Raffaele Landolfo
Keyword(s):  
Structural Response ◽  
Time History ◽  
Seismic Behaviour ◽  
Steel Moment Resisting Frames ◽  
Residual Drift ◽  
Moment Resisting Frames ◽  
Drift Ratio ◽  
Nonlinear Time History Analyses ◽  
Moment Resisting ◽  
Nonlinear Time History

In recent decades, several passive energy dissipation systems have been conceived in order to minimize the damage in structural and non-structural components of either new or existing buildings. In this study, the use of friction damped tension-compression diagonal braces for seismic upgrading of a steel moment resisting frames is investigated. To this aim, nonlinear time history analyses have been carried out on a set of representative frames with and without friction damped braces. In the nonlinear time history analyses, two sets of natural accelerograms compatible with seismic hazard levels of 10% and 2% probability of exceedance in 50 years have been considered. Under these records, the structural response has been comparatively investigated in terms of the maximum inter-storey drift ratio, maximum storey acceleration, residual drift ratio and displacement demand for the friction device. The results clearly highlighted that the application of friction damped braces allows reducing the damages to the main structural elements, thus significantly improving the seismic behaviour of the frame.

scholarly journals Performance Evaluation of Friction Damped Braced Steel Frames under Simulated Earthquake Loads

1987 ◽  
Vol 3 (1) ◽  
pp. 57-78 ◽  
Author(s):  
A. Filiatrault ◽  
S. Cherry
Keyword(s):  
Time History ◽  
Superior Performance ◽  
Braced Frame ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Earthquake Simulator ◽  
Building Systems ◽  
Moment Resisting ◽  
Seismic Tests ◽  
Brake Lining

This paper presents the results obtained from tests of a new friction damping system, which has been proposed in order to improve the response of steel Moment Resisting Frames (MRF) and Braced Moment Resisting Frames (BMRF) during severe earthquakes. The system consists of a mechanism containing brake lining pads introduced at the intersection of frame cross-braces. Seismic tests of a three storey Friction Damped Braced Frame (FDBF) model were performed on an earthquake simulator table. The experimental results are compared with the findings of an inelastic time-history dynamic analysis. The results clearly indicate the superior performance of the FDBF compared to conventional building systems.

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