scholarly journals Evaluation of behavior and performance of the braced/ unbraced four story of steel frame with semi rigid connection

2019 ◽  
Vol 270 ◽  
pp. 01002
Author(s):  
Daniel Rumbi Teruna
Keyword(s):  
Stiffness Parameter ◽  
Braced Frame ◽  
Analysis And Design ◽  
Moment Resisting Frame ◽  
Story Drift ◽  
Moment Resisting ◽  
Inelastic Behaviour ◽  
Rigid Connection ◽  
And Performance ◽  
The Moment

Structural analysis and design with taken into account the flexibility of the beam to the column connections of steel frameworks takes on importance of the growing development and utilization of new commercial software. However, for design purposes, the beam to the column connection are usually considered to be either pinned or fully rigid, and drastically simplifies the analysis and design procedures. In this paper, a four story of unbraced and concentric braced steel moment resisting frame having different connection stiffness is analysed using linear and nonlinear static procedure. In the finite element modelling, the semi rigid connection is modelled by rotational spring having linear moment and rotation relationship. To account the inelastic behaviour of beam and column members, concentrated plastic hinges based on FEMA 356 are applied for both ends of the member. It was found that, the response quantity of the unbraced frame are influenced by the flexibility connection. However, for the braced frame the effect of the initial connection stiffness parameter on the response quantity can be neglected due to present of the braces. Furthermore, the higher the initial connection stiffness parameter, the smallest the story drift index. Moreover, the present of the braces at the moment resisting frame (braced frame) reduce the sensitivity of the connection stiffness on the behaviour and the performance frame under consideration.

scholarly journals Evaluation of Modified Fish-Bone Model for Estimating Seismic Demands of Irregular MRF Structures

2018 ◽  
Author(s):  
Amin Haghighat ◽  
Ashkan Sharifi
Keyword(s):  
Ground Motions ◽  
Fish Bone ◽  
Seismic Demands ◽  
Error Measure ◽  
Ductility Demand ◽  
Earthquake Records ◽  
Moment Resisting Frame ◽  
Different Types ◽  
Story Drift ◽  
Moment Resisting

This paper evaluates the accuracy of the Modified Fish-Bone (MFB) model for estimating the maximum inter-story drift ratio of irregular moment resisting frame (MRF) structures. To make this model applicable to irregular MRF structures, some modifications are made to the MFB formula. In order to evaluate the accuracy of the MFB model, several irregular frames with different types of irregularities are considered when subjected to different ground motions with different intensities. A local and a global error measure are defined and they are calculated for different frame models subjected to different earthquake records. The effects of different irregularities, ductility demand and frame height on the accuracy of the MFB model are investigated. Based on the results obtained from this evaluation, two simple and effective approaches are suggested to improve the MFB models.

scholarly journals COMPARATIVE STUDY OF THE BEHAVIOUR OF BUILDING STRUCTURE OF HOTEL DAFAM LOTUS JEMBER BY USING MOMENT RESISTING FRAME AND ECCENTRICALLY BRACED FRAME

2018 ◽  
Vol 2 (01) ◽  
pp. 13
Author(s):  
Reza Kurniawan ◽  
Dwi Nurtanto ◽  
Gati Annisa Hayu
Keyword(s):  
Axial Force ◽  
Shear Force ◽  
Steel Structure ◽  
System Structure ◽  
Braced Frame ◽  
Eccentrically Braced Frame ◽  
Moment Resisting Frame ◽  
Concentrically Braced Frame ◽  
Moment Resisting ◽  
Short Link

Eccentrically Braced Frame (EBF) is one of several types of braces that can be used in steel building. EBF has a good stiffness and ductility to withstand earthquake load. In EBF itself there are 3 types of links, namely: Long Link, Intermediate Link, and Short Link. Meanwhile, MRF of Moment resisting Frame is a structural system where the beams and columns are connected rigidly. MRF has a good ductility in accepting load even it has no lateral braces installed. In this research the Dafam Lotus Jember hotel consisting of 10 floors with total height of 33,6 m is modeled as a MRF system structure and steel structure equipped with EBF short link. The objective of this research is to compare the effectiveness of EBF and MRF in terms of displacement, axial force, shear force, and moment occurring in buildings. The modeling results show that EBF with short link has smaller displacement value compared to MRF. The difference between the two is 86,99%. In terms of axial force, shear force, and moment, EBF has smaller values than MRF. The differences are 79,76%, 53,91%, and 10,48% respectively. These results indicate that EBF has better capacity compared to MRF. Indonesia merupakan negara yang memiliki tingkat intensitas kegempaan yang tinggi. Ini menjadikan Indonesia tidak terhindarkan dari dampak negatif yang akan ditimbulkan oleh gempa bumi, yaitu menyebabkan kerusakan insfrastruktur fisik. Peraturan gempa SNI 03-1726-2012 membahas mengenai bresing sebagai salah satu alternatif yang dapat digunakan untuk menangani masalah gempa. Eccentrically Braced Frame (EBF) adalah salah satu jenis bresing yang memiliki kekakuan dan daktilitas yang baik jika dibandingkan dengan Concentrically Braced Frame (CBF) yang hanya memiliki kekakuan yang baik. Selain itu terdapat pula Moment Resisting Frame (MRF) yaitu salah satu sistem struktur yang memiliki sifat daktail. Melihat permasalahan yang ada, maka pembahasan ini bertujuan untuk membandingkan efektivitas dari EBF menggunakan short link dengan MRF apabila diaplikasikan pada bangunan Hotel Dafam Lotus Jember 10 lantai yang memiliki tinggi 33,6 m. Adapun efektivitas yang dibadingkan disini adalah nilai story displacement dan gaya dalam (momen, gaya geser, dan gaya aksial) yang terjadi. Hasil analisa dengan bantuan program analisa struktur menunjukkan bahwa EBF menggunakan short link memiliki nilai yang lebih kecil dibandingkan dengan MRF dalam menerima beban yang bekerja. Dari segi story displacement, selisih prosentasenya adalah 86,99% sedangkan untuk gaya dalam yang meliputi momen, gaya geser, dan gaya aksial, selisihnya secara berturut-urut adalah 79,76%, 53,91% dan 10,48%. Hal ini menunjukkan bahwa EBF menggunakan short link lebih efektif jika dibandingkan dengan MRF.

Performance of School Buildings in Turkey During the 1999 Düzce and the 2003 Bingöl Earthquakes

2009 ◽  
Vol 25 (2) ◽  
pp. 239-256 ◽  
Author(s):  
Turel Gur ◽  
AliCihan Pay ◽  
Julio A. Ramirez ◽  
Mete A. Sozen ◽  
Arvid M. Johnson ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
School Buildings ◽  
Floor Plan ◽  
Structural System ◽  
Concrete Frames ◽  
Structural Walls ◽  
Concrete Walls ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
The Moment

Several school buildings were surveyed in the disaster areas of the Marmara (17 August 1999, [Formula: see text]), Düzce (12 November 1999, [Formula: see text]), and Bingöl (1 May 2003, [Formula: see text]) earthquakes in Turkey. Among them, 21 reinforced concrete buildings were found to have an identical floor plan. Lateral load resisting structural system consisted of reinforced concrete frames (moment-resisting frame) in 16 of the buildings and structural concrete walls integrated with the moment-resisting frame (dual system) in the remaining five buildings. The number of stories above ground in these buildings ranged from two to four. These school buildings provide a nearly ideal test of the effect of a single important structural characteristic on the performance of buildings with structural designs that are uniform in all other respects. Our observation is that the presence of structural walls improves the behavior of reinforced concrete systems drastically.

scholarly journals IMPACT OF INTRODUCING SEMI-RIGID MOMENT FRAMES ON SEISMIC RESPONSE OF BRACED FRAMES

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mahmoud Faytarouni ◽  
Onur Seker ◽  
Bulent Akbas ◽  
Jay Shen
Keyword(s):  
Braced Frames ◽  
Seismic Evaluation ◽  
Moment Frames ◽  
Moment Frame ◽  
Braced Frame ◽  
Shear Connections ◽  
Seismic Force ◽  
Steel Building ◽  
Story Drift ◽  
Moment Resisting

Maximum seismic inelastic drift demand in a steel building with braced frames as primary seismic-force-resisting (SFR) system tends to concentrate in few stories without considering inherent participation of designed gravity-force-resisting (GFR) system in actual structural stiffness and strength. The influence of GFR system on stiffness and strength can be taken into account by considering the composite action in beam-to-column shear connections that exist in modern steel building construction to form actual semi-rigid moment-resisting frames. Therefore, modeling semi-rigid moment frames as an equivalent to the GFR system in braced frame buildings could be utilized as a representative to the strength provided by gravity frames. This paper presents a seismic evaluation of a six-story chevron braced frame, with and without semi-rigid moment frame. Four different cases are investigated under a set of ground motions and results are discussed in terms of story drift distribution along the height. The results pointed out that the current findings lay a foundation to conduct further investigation on the seismic performance of braced frames as designed SFR system together with GFR system.

Seismic response of concentrically braced dual steel frames

1993 ◽  
Vol 20 (4) ◽  
pp. 672-687 ◽  
Author(s):  
A. K. Jain ◽  
R. G. Redwood ◽  
Feng Lu
Keyword(s):  
Seismic Response ◽  
Steel Frames ◽  
Dual System ◽  
Seismic Load ◽  
Braced Frame ◽  
Moment Resisting Frame ◽  
Inelastic Analysis ◽  
Concentrically Braced ◽  
Moment Resisting ◽  
The Impact

Concentrically braced steel frames are one of the most commonly used structural systems because of their structural efficiency, simplicity to analyze and design, and ease of construction and repair. Canadian design codes provide specifications for their design under seismic loading based on the large amount of knowledge related to their seismic response accumulated over the past two decades. This paper examines the impact of a dual system with a moment resisting frame acting in parallel with the concentrically braced frame. Four different frames were designed in accordance with the National Building Code of Canada and CSA-S16.1-M89, and their inelastic responses are studied under the action of both monotonically increasing load and seismic load. The relative strengths and stiffnesses of the frames comprising the dual systems were varied. The ductility demands on members, and overall building deflections and storey drifts, were examined under the action of ten earthquake records. It is concluded that improved performance such as reduced ductility demand and improved uniformity of the distribution of yield throughout the structure can be achieved. However, the stiffness and strength in the moment resisting frame necessary to provide marked improvement must be a significant proportion of those of the braced frame. Key words: structural engineering, earthquakes, inelastic analysis, concentric bracing, dual system, steel, buckling.

Performance Evaluation of Semi Precast Concrete Beam-Column Connections with U-Shaped Strands

2014 ◽  
Vol 17 (11) ◽  
pp. 1585-1600 ◽  
Author(s):  
Sang-Su Ha ◽  
Seung-Hun Kim ◽  
Moon Sung Lee ◽  
Jeong-Ho Moon
Keyword(s):  
Performance Evaluation ◽  
Precast Concrete ◽  
Stress Transfer ◽  
Structural System ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Column Joint ◽  
Seismic Regions ◽  
Moderate Seismic Regions ◽  
And Performance

In this study, a new precast concrete (PC) beam-column joint of moment resisting frame applicable for moderate seismic regions is proposed. A semi PC beam-column connection with U-shaped strands is developed in an attempt to improve workability and provide effective stress transfer mechanism at the joint. The structural system consists of PC beams with U-shaped strands, PC columns, PC slabs, and topping concrete. A series of three interior and three exterior semi PC joint specimens was tested to investigate the structural behavior of the system subjected to the lateral cyclic load. Key test variables are the number of strands placed in the PC beam and the presence or absence of the transverse reinforcements at the connection. The experiment and performance evaluation of the system were conducted in accordance with ACI T1.1–01 (2001). According to the test results, the proposed structural system with transverse reinforcements at the joint is sufficient to use in moderate seismic regions.

scholarly journals ANALISIS PERIODA BANGUNAN DINDING GESER DENGAN BASE ISOLATOR AKIBAT GAYA GEMPA

Teras Jurnal ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 263
Author(s):  
Mul Muliadi Adi ◽  
M. Kabir Kabir Ihsan
Keyword(s):  
Seismic Design ◽  
Time History ◽  
Shear Wall ◽  
Braced Frame ◽  
Moment Resisting Frame ◽  
Rigid Frame ◽  
Base Isolator ◽  
Non Linear ◽  
Moment Resisting ◽  
Performance Based Seismic Design

Bangunan yang hancur oleh gempa dapat dicegah dengan memperkuat struktur bangunan terhadap gaya gempa yang bekerja padanya. Perkuatan bangunan dapat dilakukan dengan memperkaku bangunan dalam arah lateral yaitu <em>moment resisting frame</em> (<em>rigid frame</em>), <em>braced frame</em> dan <em>shear wall</em>. Bangunan dinding geser merupakan salah satu jenis <em>bangunan</em> tahan gempa gedung beton bertulang menggunakan sistem rangka struktur yang dikombinasikan. Kinerja gedung akan bertambah dan menjadi optimal jika pola penempatan <em>dinding geser</em> serta metode analisanya tepat. Sistem lainnya dalam mengurangi kerusakan bangunan akibat gempa dengan <em>performance based seismic design</em> yaitu dengan menggunakan <em>base isolator.</em>, yang memanfaatkan teknik analisa non-linear berbasis komputer untuk menganalisa perilaku inelastis struktur dari berbagai macam intensitas gerakan tanah (<em>gempa</em>), sehingga dapat diketahui kinerjanya pada kondisi kritis. Tujuan penelitian ini dilakukan untuk mengetahui perioda dalam penggunaan <em>base isolator </em>dengan yang tanpa menggunakan <em>base isolator,</em> pada bangunan sistem ganda, lantai 10 tingkat, bentuk beraturan pada bangunan dinding geser. Analisis data yang dilakukan dengan menggunakan bantuan <em>software </em>komputer <em>SAP2000</em>. Pembebanan pada gedung didasarkan pada peraturan bangunan gedung beton bertulang dan analisa dinamik <em>Time History Modal Analysi</em>s struktur dalam Tata Cara Perencanaan Ketahanan Gempa Untuk Struktur Bangunan Gedung Dan Non Gedung (SNI 1726:2012). Dari hasil penelitian ini dapat diketahui bahwa penggunaan <em>base isolator</em> memperbesar perioda alami. Nilai perioda pada dinding geser dan dinding geser <em>base isolator</em> besarnya berturut-turut 0.988 detik dan 2.465 detik. Hal ini menyebabkan gaya gempa yang bekerja menjadi lebih kecil.

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