scholarly journals The Seismic Investigation of Off-Diagonal Steel Braced RC Frames

2018 ◽  
Vol 26 (3) ◽  
pp. 49-64 ◽  
Author(s):  
Keyvan Ramin ◽  
Mahmoud R. Maheri
Keyword(s):  
Time History ◽  
Base Shear ◽  
Rc Frames ◽  
Steel Bracing ◽  
History Analysis ◽  
Out Of Plane ◽  
Ductile Steel ◽  
Frame Systems ◽  
Bracing System ◽  
Hysteresis Response

Abstract Steel bracing may be used to enhance the seismic strength of RC frames. Concentric steel bracing generally reduces ductility, which is a key component of seismic design. To overcome the problem, ductile steel brace-RC frame systems are therefore usually introduced in the form of eccentric braces. In the present study, the Off-Diagonal Bracing System (ODBS), which works as a concentric type of bracing, is investigated. In this paper the response of ODBS elements to cyclic loading is first explored and compared with those of other types of bracing such as X-bracing and inverted-V bracing systems. The time history analysis responses and cyclic hysteresis responses of a number of lowrise to mid-rise RC frames retrofitted with different types of bracing systems are then evaluated and compared. It is shown that under seismic excitation, a much reduced base shear is experienced by frames retrofitted with ODBS compared to other bracing systems. The results of time history and cyclic hysteresis response analyses also indicate a far greater energy dissipation capacity and ductility for the ODBS compared to other bracing systems. It is also concluded that ODBS performs best in lowrise frames. The out-of-plane buckling response of the ODBS is also investigated, and it is shown that a double-plated central connection can control such an adverse response.

scholarly journals Effect of the Improved Pall Friction Damper on the Seismic Response of Steel Frames

2017 ◽  
Vol 7 (4) ◽  
pp. 1833-1837 ◽  
Author(s):  
P. H. Sarjou ◽  
N. Shabakhty
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Steel Frames ◽  
Time History ◽  
Friction Damper ◽  
Base Shear ◽  
Absorbed Energy ◽  
Steel Bracing ◽  
History Analysis ◽  
Energy Absorbing

Energy-absorbing dampers are used to reinforce structures which are vulnerable to earthquakes. This study evaluates the performance of Improved Pall Frictional Dampers (IPFD) which is a type of Pall Frictional Damper (PFD). For this purpose, this study compares the performances of steel frames with concentric steel bracing reinforced by IPFD and steel frames with concentric steel bracing with no damper. Frames with different stories and pans were modelled in sap2000 and exposed to accelerograms of earthquakes for non-linear time history analysis. Results of analysis were studied; parameters such as story displacement, base shear and absorbed energy were compared in steel frames with damper and without damper.

scholarly journals Seismic Performance of Multistorey RC Frame Building With The Soft Storey and Masonry Infill

2021 ◽  
pp. 650-656
Author(s):  
Kugan K ◽  
Mr. Nandha Kumar P ◽  
Premalath J
Keyword(s):  
Time History ◽  
Seismic Loading ◽  
Rc Frame ◽  
Base Shear ◽  
Maximum Displacement ◽  
Soft Storey ◽  
Masonry Infills ◽  
Frame Building ◽  
History Analysis ◽  
Rc Frame Building

In this study, four geometrically similar frames having different configurations of masonry infills, has been investigated. In this article attempts are made to explain the factors that impact the soft storey failure in a building are compared with different type of infill. That is Four models like RC bare frame, RC frame with brick mansonry infill, RC frame with brick infill in all the storeys exept the firstsoft storey, RC frame with inverted V bracing in the soft storey. Time history analysis has been carried out for a G+8 multistoried building to study the soft storey effect at different floor levels using E tabs software. The behavior of RC framed building with soft storey under seismic loading has been observed in terms of maximum displacement ,maximum storey drift, base shear and storey stiffness as considered structure.

scholarly journals Review on Seismic Analysis of Multistoried Building in Hilly Region

2021 ◽  
Vol 9 (12) ◽  
pp. 73-79
Author(s):  
Harsh Joshi
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Center Of Mass ◽  
Time History ◽  
Lateral Loads ◽  
Base Shear ◽  
Building Frames ◽  
Building Frame ◽  
History Analysis ◽  
Hilly Region

Abstract: Due to sloping land and high seismically active zones, designing and construction of multistory buildings in hilly regions is always a challenge for structural engineers. This review paper focuses to establish a review study on the Possible Types of building frame configuration in the hilly region and he behavior of Such building frames under seismic loading conditions, and (3) The recent research and developments to make such frames less vulnerable to earthquakes. This paper concludes that the dynamics characteristics of such buildings are significantly different in both horizontal and vertical directions, resulting in the center of mass and center of stiffness having eccentricity at point of action and not vertically aligned for different floors. When such frames are subjected to lateral loads, due to eccentricity it generates torsion in the frame. Most of the studies agree that the buildings resting on slanting ground have higher displacement and base shear compared to buildings resting on plain ground and the shorter column attracts more forces and undergoes damage when subjected to earthquake. Keywords: Building frame configuration, Seismic behavior, Dynamic characteristics, Response spectrum analysis, time history analysis.

Optimization Design of Large Span Cable-Stayed Bridge in High Seismic Risk Zone

2013 ◽  
Vol 353-356 ◽  
pp. 2015-2019
Author(s):  
Zhi Hua Xiong ◽  
Yun Cheng Feng ◽  
Song Lin Song ◽  
Jiang Bo Wang
Keyword(s):  
Optimization Design ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Seismic Safety ◽  
Seismic Demands ◽  
Large Span ◽  
Cable Stayed Bridge ◽  
History Analysis ◽  
Ductile Steel ◽  
Nonlinear Time History

To ensure seismic safety of a large span cable-stayed bridge, two alternative pylon shapes and section types were studied. Nonlinear time history analysis was performed in the context. It is found that the A-shaped pylon is much stiffener than the H-shaped pylon in terms of deformation. The steel A-shaped pylon can significantly reduce the seismic demands of the key member including tower drift and moment. A ductile steel link between towers is proposed for the optimization of design in the paper. The A-shaped reinforced concrete tower with ductile steel link was proved to be a relatively balanced plan considering engineering, aesthetic and economic factors.

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.

scholarly journals Isolating system using U Shaped steel damper

2021 ◽  
Vol 309 ◽  
pp. 01136
Author(s):  
Siripuram Vamshisheela ◽  
Atulkumar Manchalwar
Keyword(s):  
Base Isolation ◽  
Ground Motions ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Base Shear ◽  
Energy Device ◽  
History Analysis ◽  
Structural Responses ◽  
Nonlinear Time History ◽  
Story Building

In this work the performance of U-Shaped Steel Isolator is evaluated for a 5-story building subjected to seismic and blast vibrations. The structure is analysed using SAP 2000 software and a nonlinear time history analysis is carried out. The effectiveness of using base isolation is studied by comparing the structural responses of the building with isolator and without isolator and noticeable difference was observed. As the U-Shaped isolator absorbs the energy in all directions, it effectively controls the structural responses. In this study, the building is subjected to four different seismic and four different blast induced ground motions. It was observed that by the use of supplementary energy device there is reduction in top story acceleration, base shear and less deformation in the structure. This study concludes that the use of isolator has been effective in minimizing structural responses.

scholarly journals Evaluasi Geser Dasar Minimun pada SNI 1726-2012

2019 ◽  
Vol 10 (2) ◽  
pp. 166-184
Author(s):  
Johnny Setiawan ◽  
Iswandi Imran
Keyword(s):  
Linear Time ◽  
Damage Control ◽  
Time History ◽  
Time History Analysis ◽  
Performance Level ◽  
Life Safety ◽  
Base Shear ◽  
History Analysis ◽  
Story Drift ◽  
Immediate Occupancy

Terdapat cukup banyak perubahan pada SNI 1726-2012, salah satunya adalah adanya persyaratanbatas geser dasar minimum (minimum base shear) yang tidak ada pada peraturan sebelumnya.Metode yang akan dilakukan adalah bangunan gedung dengan klasifikasi ketinggian rendah,sedang dan tinggi akan dianalisis dengan menerapkan geser dasar minimum dan tanpa geser dasarminimum. Analisis yang akan digunakan adalah analisis ragam spektrum respons (ResponsSpectrum Analysis, RSA), analisis respons riwayat waktu (Time History Analysis, THA) dananalisis respons riwayat waktu non linier (Non Linear Time History Analysis, NLTHA). Hasilanalisis menunjukkan bahwa pada peraturan SNI 1726-2012 dengan adanya persyaratan batasangeser dasar minimum dapat menjamin kinerja struktur sesuai dengan yang diharapkan.Kekhawatiran adanya batasan geser dasar minimum pada SNI 1726-2012 akan membuat desainmenjadi tidak ekonomis, ternyata tidak terbukti karena tidak memberikan pengaruh signifikanpada hasil desain, khususnya untuk bangunan dengan kategori ketinggian rendah dan sedang.Untuk bangunan dengan klasifikasi bangunan tinggi, analisis dan desain dengan memperhitungansyarat batasan geser dasar minimum dan tanpa memperhitungkan geser dasar minimum dapatmemberikan hasil desain yang baik, tetapi pengecekan pada Level Kinerja (Performance Level)sesuai dengan story drift menunjukkan bahwa analisis dengan memperhitungkan syarat geser dasarminimum memberikan hasil dengan level kinerja yang cukup baik yaitu Immediate Occupancy(IO) hingga Damage Control (DO), sedangkan tanpa memperhitungkan geser dasar minimummemberikan hasil dengan level kinerja yang kurang baik yaitu Life Safety (LS) hingga StructuralStability (SS). Sedangkan pada level kinerja elemen struktur, analisis tanpa memperhitungkangeser dasar minimum menyebabkan banyak elemen struktur yang berada pada level kinerjaCollapse Prevention (CP).

scholarly journals Investigation of applying dampers in elevated water tanks using time-history analysis

2015 ◽  
Vol 4 (1) ◽  
pp. 169
Author(s):  
Ehsan Rajaie
Keyword(s):  
Dynamic Behavior ◽  
Water Storage ◽  
Time History ◽  
Time History Analysis ◽  
Storage Tanks ◽  
Base Shear ◽  
Shear Forces ◽  
History Analysis ◽  
Elevated Water ◽  
Water Tanks

In this paper, the dynamic behavior of water storage tanks in investigated. Using time-history analysis based on three major earthquakes, the performance of system is illustrated. Two conditions, first with damper and second with no damper are presented and the relevant results are compared. The main results consist of base shear forces and also maximum target displacements. 

Dynamic Time History Analysis of the Effect of Infilled Walls on the Steel Staggered-Truss System

2012 ◽  
Vol 446-449 ◽  
pp. 824-828
Author(s):  
Qing Sheng Guo ◽  
Qing Shan Yang
Keyword(s):  
Finite Element ◽  
Rare Earth ◽  
Earth Quake ◽  
Shear Force ◽  
Time History ◽  
3D Models ◽  
Base Shear ◽  
History Analysis ◽  
Dynamic Time ◽  
Staggered Truss System

A structure with steel staggered-truss (SST) system is numerically investigated in this paper, utilizing the finite element 3D simulation analytial soft ware ETABS. Two different 3D models considering or ignoring the stiffness of infilled walls (SIW) are analyzed with Dynamic Time History method including storey drift and equivalent base shear force under frequent earth quake and rare earth quake. Results indicate that the effect of the SIW is prominent and should be considered.

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