scholarly journals Steel Frames Exposed to Severe Ground Motions: Use of Viscous Dampers and Buckling Restrained Braces to Dissipate Earthquake Induced Energy

2021 ◽  
Author(s):  
Osman Hansu ◽  
Esra Mete Guneyisi
Keyword(s):  
Steel Frames ◽  
Structural Response ◽  
Time History ◽  
Base Shear ◽  
Viscous Dampers ◽  
Finite Element Program ◽  
Buckling Restrained Braces ◽  
Interstorey Drift ◽  
Element Program ◽  
Nonlinear Time History

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as the innovative seismic protection devices. For this, 4, 8 and 12 storey steel frames were designed with 6.5 m equal span length and 4 m storey height. Thereafter, the VDs and BRBs were placed over the height of each frame considering three different configurations. The structures were modeled using SAP2000 finite element program and evaluated by the nonlinear time history analyses subjected to the six natural accelerograms (1976 Gazlı, 1978 Tabas, 1987 Superstition Hills, 1992 Cape Mendocino, 1994 Northridge and 1999 Chi-Chi). The structural response of the structures with and without VDs and BRBs were studied in terms of variation in the displacement, interstorey drift, absolute acceleration, maximum base shear, time history of roof displacement. The results clearly indicated that the application of VDs and BRBs had remarkable improvement in the earthquake performance of the case study frames by reducing the local/global deformations in the main structural systems and satisfied the serviceability.

scholarly journals Performance comparisons of triple friction pendulum bearings with different sliding surface properties

2021 ◽  
Vol 4 (3) ◽  
pp. 151-162
Author(s):  
Muhamad Zulfakar ◽  
Ali İhsan Karakaş
Keyword(s):  
Friction Coefficient ◽  
Surface Properties ◽  
Friction Surface ◽  
Time History ◽  
Radius Of Curvature ◽  
Sliding Surface ◽  
Base Shear ◽  
Finite Element Program ◽  
Element Program ◽  
Friction Pendulum

In this study the time history analyses are carried out three dimensionally for a simple five-story concrete structure seismically isolated incorporating triple friction pendulum bearings with different sliding surface properties with the help of the ABAQUS finite element program. The altering friction surface properties are friction coefficient and radius of curvature. The performances of the various isolators are compared with each other as well as with those of a fixed based structure. For this purpose, maximum relative story displacements, story accelerations and column base shear forces are investigated as seismic reactions. According to the analysis results it can be stated that the seismic reactions of isolated structures are significantly reduced when compared to those of the fixed supported structure. Additionally, when triple friction pendulum bearing isolators with different friction coefficients and friction surface radii are compared, it can be observed that increasing the friction coefficient increases the reactions of the structure while increasing the friction surface radii decreases the reactions

scholarly journals CORRELATION BETWEEN INTENSITY MEASURE PARAMETERS OF GROUND MOTION EARTHQUAKES AND STRUCTURAL RESPONSE OF MOMENT RESISTING STEEL FRAMES

2020 ◽  
Vol 32 (3) ◽  
Author(s):  
Emad Ali Elhout
Keyword(s):  
Ground Motion ◽  
Pearson Correlation ◽  
Steel Frames ◽  
Structural Response ◽  
Time History ◽  
Base Shear ◽  
Intensity Measure ◽  
Response Parameter ◽  
Drift Ratio ◽  
Moment Resisting

Identify and select a suitable ground motion intensity measure (IMs) parameters associated with the structural response to specific levels of damages or collapse in structures are very important in the seismic response of structural analyses. This paper investigated the correlation between 25 intensity measure (IMs) parameters of earthquakes and the structural response parameters of 3-, 6- and 12-story moment resisting steel frames (MRSFs). Nonlinear time history analyses are performed for these frames under near- and far-source ground motion records. The maximum story drift ratio (MSDR), the roof drift ratio (RDR), and the maximum base shear force (SF) are chosen as the structural response parameters. The Pearson correlation coefficient with the regression analyses is utilized to display the correlation between the structural response parameter and the ground motion IMs parameters. The results reveal that MSDR appears to be a suitable engineering demand parameter to correlate with most of the ground motion IMs parameters compared to both the RDR and the SF parameters. Also, Max. Incremental velocity (MIV) parameter is considered as the highest correlated IMs parameters with MSDR in both near- and far-source earthquakes.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

scholarly journals Nonlinear time-history earthquake analysis for steel frames

Heliyon ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. e06832
Author(s):  
Phu-Cuong Nguyen ◽  
Thanh-Tuan Tran ◽  
Trong Nghia-Nguyen
Keyword(s):  
Steel Frames ◽  
Time History ◽  
Nonlinear Time History

Pseudodynamic Test of a Deficient RC Frame Strengthened with Buckling Restrained Braces

2019 ◽  
Vol 35 (3) ◽  
pp. 1163-1187 ◽  
Author(s):  
Ramazan Ozcelik ◽  
Elif Firuze Erdil
Keyword(s):  
Time History ◽  
Shear Capacity ◽  
Test Method ◽  
Nonlinear Time History Analysis ◽  
Rc Frame ◽  
Test Results ◽  
Base Shear ◽  
Braced Frame ◽  
Pseudodynamic Test ◽  
Buckling Restrained Braces

Three story–three bay reinforced concrete (RC) frames with and without chevron braces were tested using the continuous pseudodynamic test method. New steel–concrete composite lateral load–carrying members called Buckling Restrained Braces (BRBs) were used as chevron brace members while retrofitting the RC frame. The BRBs were fitted to the interior span of the RC frame by using anchorage rods. The chevron braced frame was observed to be effective in controlling interstory drift. The test results indicated that retrofitting with BRBs was beneficial in resisting deformation without significant damage under simulated ground motions. Furthermore, significant yielding that occurred on the core plate of the BRBs enabled the braced frame to dissipate energy induced by dynamic loading. The test results were compared with the results of the nonlinear time-history analysis. The analysis results were capable of estimating the base shear capacity and displacement demands with reasonable accuracy.

The Influence Analysis of Mechanical Behavior between Pile and Soil on End Bearing Pile Foundation’s Dynamic Characteristic

2014 ◽  
Vol 580-583 ◽  
pp. 1481-1485
Author(s):  
Wei Hu ◽  
Ya Hui Zhang ◽  
Ying Zhang
Keyword(s):  
Mechanical Behavior ◽  
Structural Model ◽  
Ground Surface ◽  
Time History ◽  
Horizontal Displacement ◽  
Shearing Stress ◽  
Maximum Acceleration ◽  
Finite Element Program ◽  
Element Program ◽  
End Bearing Pile

Dynamic structural model of saturated soil was introduced, and combining with the finite element program, the finite-infinite element models of end bearing pile foundations was established. Four models of interface between pile and soil including absolutely jointed, slippage, crack, both slippage and crack were considered to study the interface’s effect on pile foundation’s dynamic characteristics. The results were as follows: the interface’s mechanical behavior has a little influence on the distributions of pile section’s shearing stress and horizontal displacement. Pile section’s shearing stress reaches the maximum near the ground surface when interface is slippage or crack, and reaches the minimum ones when interface is absolutely jointed. Horizontal displacement could be divided into two phases and the ground surface is the dividing line. The interface’s behavior greatly changes the distribution of acceleration time-history curve. To different models, the maximum acceleration all appears at the ground surface. On the whole, the interface’s behavior has significant influence on end bearing pile, which should be pay attention in the design from now on.

Energy-Dissipation Mechanisms and Seismic Design Recommendation of Eccentrically Braced Steel Frames

2011 ◽  
Vol 71-78 ◽  
pp. 3662-3665
Author(s):  
Bao Cheng Zhao ◽  
Qiang Gu
Keyword(s):  
Plastic Deformation ◽  
Energy Dissipation ◽  
Seismic Design ◽  
Steel Frames ◽  
Shell Element ◽  
Elastic Stiffness ◽  
Collapse Mechanism ◽  
Finite Element Program ◽  
Earthquake Load ◽  
Element Program

Eccentrically braced steel frames are a lateral load-resisting system which apply high intensity area and it can provide the high elastic stiffness that met higher steel building drift requirement. This paper first provides an introduction of Forces in links and Energy dissipation mechanisms of eccentrically braced steel frames. In that Eccentrically braced steel frames will collapse after the link beams go into plastic deformation under earthquake load, A new analytical model which include shell element apply to link beams with large deformation and plastic deformation and beams element apply to other parts of structure is presented in this paper for analyzing eccentrically braced steel frames energy-dissipation behavior and collapse mechanism. Computer program is complied. After this paper applies nonlinear finite element program to analyze the behaviors of eccentrically braced steel frames under cyclic load, the seismic design recommendations of eccentrically brace are presented.

Strengthening Research in the Longitudinal Frames of Prefabricated Structures with Viscous Dampers

2013 ◽  
Vol 671-674 ◽  
pp. 782-785
Author(s):  
Bin He ◽  
Jin Lai Pang ◽  
Cheng Qing Liu
Keyword(s):  
Seismic Performance ◽  
Pushover Analysis ◽  
Vertical Direction ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Viscous Dampers ◽  
Existing Building ◽  
Concrete Frame ◽  
Uniform Drift ◽  
Nonlinear Time History

For the lack of research in the longitudinal frame of prefabricated structure for its weak lateral stiffness, pushover analysis is conducted to evaluate the seismic performance of a fabricated concrete frame. Based on case study, the strengthening strategies with viscous dampers are analyzed. In view of the undesirable drift distribution and failure mode in the existing building, it is believed that arrangement of dampers should be designed to attain a uniform drift distribution. Based on the nonlinear time history analysis method, the strategy of damper allocation in vertical direction of the structure is investigated .Results indicate that a proper design might be attained based on the property of existing system, leading to a uniform drift distribution and better seismic performance.

scholarly journals Investigation of PTMD System Affected by Parkfield Near-Field Earthquake

2017 ◽  
Vol 11 (4) ◽  
pp. 70 ◽  
Author(s):  
Ali Vatanshenas
Keyword(s):  
Near Field ◽  
Structural Response ◽  
Time History ◽  
Steel Structure ◽  
Roof Displacement ◽  
Base Shear ◽  
Maximum Acceleration ◽  
Existing Structures ◽  
History Analysis ◽  
Reduction Methods

Earthquake is considered as the main destructive and collapsing factor of structures in near-fault zones, so design new structures and retrofitting existing structures in order to decrease structural responses is an unavoidable matter. One of the structural response reduction methods is using of TMDs. In this paper, a two-dimensional 10-storey steel structure as three structural models without PTMD, with a PTMD at the highest level and ten PTMDs with different characteristics at all levels with the Modal-FNA time-history analysis method under acceleration records with directivity and without directivity of Parkfield 2004 earthquake at the angle of the maximum acceleration response in the first mode period of structure after rotating the acceleration records at the station with directivity and its corresponding angle at the station without directivity were compared to each other in terms of the roof displacement, the input energy and the base shear. It was observed that the structure behavior in the case of using only one PTMD is better, but in the case where ten PTMDs with relative smaller masses were used compared to the case where only one PTMD was used is also with roof displacement reduction.

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.

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