Research about Influence of Strength Variability on Seismic Performance of Weak Shear Type Concentrically-Braced Steel Frames

2011 ◽  
Vol 243-249 ◽  
pp. 1396-1400
Author(s):  
Yong Sheng Qi ◽  
Feng Hua Zhao ◽  
Jun Wen Zhou
Keyword(s):  
Seismic Performance ◽  
Steel Frames ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Analysis Method ◽  
History Analysis ◽  
Concentrically Braced ◽  
Shear Type ◽  
Nonlinear Time History ◽  
Strength Variability

Influence of strength variability of braces on the weak shear type concentrically-braced steel frames is studied by pushover and nonlinear time history analysis method, which leads to a conclusion that the overstrength of brace has obviously detrimental influence on the seismic performance of the structure, induces stronger seismic reaction and higher seismic risk. Another valuable discovery is that after the area of the braces of weak shear type centrically-braced steel frames are determined according to the requirement of current codes, the designer can intentionally specify the structural steel of comparatively low strength (for example, the 2nd group in the paper taking 70% strength of steel Q235) for the brace, which can provide the structure more excellent seismic performance.

Correlation between Damage Indexes in Knee Bracing Frames Subjected to Earthquakes

2011 ◽  
Vol 255-260 ◽  
pp. 2350-2354
Author(s):  
Kamran Faraji ◽  
Mahmoud Miri
Keyword(s):  
Structural Damage ◽  
Steel Frames ◽  
Time History ◽  
Deformation Energy ◽  
Hysteretic Behavior ◽  
Nonlinear Time History Analysis ◽  
Damage Level ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Earthquake Accelerograms

For vulnerability assessment of structures, different damage indexes have been established by researchers that estimate the structural damage level. In these indexes different parameters have been used for calculating structural damage level. In this paper, damage indexes based on deformation, energy and cycle hysteretic behavior are investigated in order to find a correlation between their numerical values. The selected damage indexes are calculated and compared by applying them in nonlinear time history analysis of low and intermediate rise knee braced steel frames subjected to a set of seven earthquake accelerograms. Correlations between various indexes have been presented graphically and approximate conversion formulas are also provided.

Study on a Roller-Footing Isolated Single-Pier System

2012 ◽  
Vol 204-208 ◽  
pp. 2658-2661 ◽  
Author(s):  
Biao Wei ◽  
Shan Shan Li
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Internal Force ◽  
Nonlinear Time History Analysis ◽  
Isolation System ◽  
History Analysis ◽  
Object Of Study ◽  
Design Earthquake ◽  
Nonlinear Time History ◽  
Rolling Balls

As to improve bridges’ seismic performance, horizontal earthquake was isolated at the bottom of piers. With one pier system as the object of study, adopting nonlinear time history analysis analyzed the un-isolation system, the traditional isolation system and the new isolation system’s seismic performance especially when the actual earthquake was different from the design earthquake, in which the new isolation system was based on rolling balls. Results shows, as for the new isolation system, the internal force is independent of earthquake accelerations and earthquake periods, therefore, sympathetic vibration will not exist, and the internal force is always too small to destroy the system.

scholarly journals Evaluation of Seismic Performance and Effectiveness of Multiple Slim-Type Damper System for Seismic Response Control of Building Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
David Kim ◽  
Eun Hee Sung ◽  
Kwan-Soon Park ◽  
Jaegyun Park
Keyword(s):  
Cost Effectiveness ◽  
Seismic Performance ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Damping Capacity ◽  
Building Structures ◽  
History Analysis ◽  
Loading Tests ◽  
Nonlinear Time History ◽  
Real Scale

This paper presents the evaluation of seismic performance and cost-effectiveness of a multiple slim-type damper system developed for the vibration control of earthquake excited buildings. The multiple slim-type damper (MSD) that consists of several small slim-type dampers and linkage units can control damping capacity easily by changing the number of small dampers. To evaluate the performance of the MSD, dynamic loading tests are performed with three slim-type dampers manufactured at a real scale. Numerical simulations are also carried out by nonlinear time history analysis with a ten-story earthquake excited building structure. The seismic performance and cost-effectiveness of the MSD system are investigated according to the various installation configurations of the MSD system. From the results of numerical simulation and cost-effectiveness evaluation, it is shown that combinations of the MSD systems can effectively improve the seismic performance of earthquake excited building structures.

Sensitivity analysis of the influence of ground motion intensity levels on the seismic behavior of steel frames in assessment of the target displacement considering near-fault effects

2020 ◽  
Vol 47 (4) ◽  
pp. 470-486
Author(s):  
Alireza Esfahanian ◽  
Ali Akbar Aghakouchak
Keyword(s):  
Ground Motions ◽  
Steel Frames ◽  
Time History ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Seismic Demands ◽  
Near Fault ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Far Fault

Nonlinear time-history analysis conducted as part of a performance-based seismic design approach often require that the ground motion records are selected and then scaled to a specified level of seismic intensity. In such analyses, besides an adequate structural model, a set of acceleration time-series is needed as the most realistic representation of the seismic action. In this paper, the effects of scaling procedure on seismic demands of steel frames are investigated. To this, two special steel moment-resisting frames with considerable higher mode effects, and two sets of ground motions, including near-fault and far-fault motions are considered. Moreover, three scaling procedures are introduced for performing nonlinear dynamic time-history analysis of structures. Among different demands, lateral roof displacement and interstory drift are selected as seismic demands. The height-wise distribution of demands shows that the inelastic seismic demands of the near-fault pulse-like ground motions differ considerably from those of far-fault ones. These results show that the story drifts are mostly larger for far-fault motions in the upper story levels in comparison to near-fault records and in the lower floors, the reverse is true. Thus, the scaling procedures directly affect the results of seismic demands and choosing different methods would result in varying responses. Moreover, a low-cost and fairly effective procedure is proposed to estimate the target displacement demands of buildings from response-spectrum analyses, considering near-fault effects. The precision of this method is verified by nonlinear time-history analysis results, as the benchmark solution, and acceptable improvements have been achieved.

Seismic Performance Evaluation of a Steel-Concrete Hybrid Frame-Tube High-Rise Building Structure

2011 ◽  
Vol 137 ◽  
pp. 149-153 ◽  
Author(s):  
Huan Jun Jiang ◽  
Bo Fu ◽  
Lao Er Liu
Keyword(s):  
Numerical Analysis ◽  
Seismic Performance ◽  
Mainland China ◽  
Time History ◽  
Tall Buildings ◽  
Hybrid Structure ◽  
Nonlinear Time History Analysis ◽  
Seismic Performance Evaluation ◽  
History Analysis ◽  
Nonlinear Time History

Due to its unique advantages, the steel-concrete hybrid structure has been widely used in tall buildings around the world. In Mainland China it has been utilized as one of the most popular structural types for super tall buildings. In this study the seismic performance of a code-exceeding tall building with the hybrid frame-tube structure to be constructed in Beijing is evaluated by numerical analysis. The analytic model of the structure is established with the aid of PERFORM-3D program, and the nonlinear time history analysis is performed by inputting four sets of earthquake ground motions. The elastic dynamic characteristics, the global displacement responses, the performance levels and the deformation demand-to-capacity ratios of structural components under different levels of earthquakes are presented. Numerical analysis results indicate that the hybrid structure has good seismic performance.

scholarly journals Comparison Study of CBFs and EBFs Bracing in Steel Structures with Nonlinear Time History Analysis

2017 ◽  
Vol 3 (11) ◽  
pp. 1157
Author(s):  
Yaseer Khademi ◽  
Mehdi Rezaie
Keyword(s):  
Time History ◽  
Steel Structures ◽  
The United States ◽  
Nonlinear Time History Analysis ◽  
Braced Frames ◽  
Concentrically Braced Frames ◽  
History Analysis ◽  
Concentrically Braced ◽  
History Of ◽  
Nonlinear Time History

Steel concentrically braced frames (CBFs) and Steel eccentricity braced frames (EBFs) are frequently used as efficient lateral load resisting systems to resist earthquake and wind loads. This paper focuses on high seismic applications where the brace members in CBFs and EBFs dissipate energy through repeated cycles of buckling and yielding. The present study evaluates in detail the design philosophies and provisions used in the United States for these systems. The results of a total of 176 analysis of nonlinear history of seismic behavior of CBFs and EBFs braces have been presented. Notable differences are observed between the performances of the CBFs and EBFs designed using American provisions. The similarities and differences are thoroughly discussed.

scholarly journals Performance of an Existing Reinforced Concrete Building Designed in Accordance to Older Indonesian Seismic Code: A Case Study for a Hotel in Kupang, Indonesia

2018 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Pamuda Pudjisuryadi ◽  
Benjamin Lumantarna ◽  
Ryan Setiawan ◽  
Christian Handoko
Keyword(s):  
Plastic Hinge ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Ground Acceleration ◽  
Seismic Code ◽  
Damage Level ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Seismic Hazard Map

The recent seismic code SNI 1726-2012 is significantly different compared to the older code SNI 1726-2002. The seismic hazard map was significantly changed and the level of maximum considered earthquake was significantly increased. Therefore, buildings designed according to outdated code may not resist the higher demand required by newer code. In this study, seismic performance of Hotel X in Kupang, Indonesia which was designed based on SNI-1726-2002 is investigated. The structure was analyzed using Nonlinear Time History Analysis. The seismic load used was a spectrum consistent ground acceleration generated from El-Centro 18 May 1940 North-South component in accordance to SNI 1726-2012. The results show that Hotel X can resist maximum considered earthquake required by SNI 1726-2012. The maximum drift ratio is 0.81% which is lower than the limit set by FEMA 356-2000 (2%). Plastic hinge damage level is also lower than the allowance in ACMC 2001.

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