scholarly journals Seismic Response Analysis of Multi-Story Steel Frames Using BRB and SCB Hybrid Bracing System

2019 ◽  
Vol 10 (1) ◽  
pp. 284 ◽  
Author(s):  
Rong Chen ◽  
Canxing Qiu ◽  
Dongxue Hao

Multi-story steel frames are popular building structures. For those with insufficient seismic resistance, their seismic capacity can be improved by installing buckling-restrained braces (BRBs), which is known for high energy dissipation capacity, and the corresponding frame is denoted as BRB frame (BRBF). However, BRBFs are frequently criticized because of excessive residual deformations after earthquakes, which impede the post-event repairing work and immediate occupancy. Meanwhile, self-centering braces (SCBs), which were invented with a particular purpose of eliminating residual deformation for the protected structures, underwent fast development in recent years. However, the damping capability of SCBs is relatively small because their hysteresis is characterized by a flag shape. Therefore, this paper aims to combine these two different braces to form a hybrid bracing system. A total of four combinations are proposed to seek an optimal solution. The multi-story steel frames installed with BRBs, SCBs, and combined braces are numerically investigated through nonlinear static and dynamic analyses. Interested seismic response parameters refer to the maximum story drift ratios, maximum floor accelerations, and residual story drift ratios. The seismic analysis results indicate that the frames using the combined bracing system are able to take the advantages of BRBs and SCBs.

2021 ◽  
Vol 18 (1) ◽  
pp. 88-99
Author(s):  
Azis Wicaksana ◽  
Anis Rosyidah

Indonesia has a code for designing a seismic-resistant building, which has always improved year after year. Start from Peraturan Perencanaan Tahan Gempa Indonesia Untuk Gedung (PPTI-UG) 1983, SNI 1726:2002, SNI 1726:2012, and the latest one is SNI 1726:2019. SNI 1726:2019 experienced some renewal on designing a seismic-resistant building. This research aims to compare spectrum response design and the structural behavior between seismic-resistant building design using SNI 1726:2012 and SNI 1726:2019. The reviewed structure behaviors are base shear force (V), drift (δmax), and story drift (Δ). The study compares the detail of the structural components as well as using SNI 2847:2013 and SNI 2847:2019. The research uses a 10-story building modeling that serves as an apartment building and located in the city of Banda Aceh. Seismic analysis using a spectrum response analysis with Special Moment Resisting Frame (SMRF) structure. The result showed that the peak acceleration (Sa) for the class sites of Medium Land (SD) and Hard Land (SC) were 11% and 26%, respectively, while for Soft Land (SE), there was no increase. The shear force in SNI 1726: 2019 has increased by 19.75% for the X direction and 19.97% for the Y direction. The increase in the shear force is directly proportional to the increase in drift and story drift. In the beam detailing and beam-column connection, there were no significant changes. While in the column detailing, there are additional provisions that cause the transverse reinforcement to be tighter.


2005 ◽  
Vol 5 (4) ◽  
pp. 271-287 ◽  
Author(s):  
Ali Mehrabian ◽  
Achintya Haldar ◽  
Alfredo Reyes-Salazar

Author(s):  
Masato Ono ◽  
Kazuhiko Iigaki ◽  
Yosuke Shimazaki ◽  
Atsushi Shimizu ◽  
Hiroyuki Inoi ◽  
...  

Japan Atomic Energy Agency (JAEA) has carried out research and development to establish the technical basis of High Temperature Gas-cooled Reactor (HTGR) by using High Temperature engineering Test Reactor (HTTR). On March 11th, 2011, the Great East Japan Earthquake of magnitude 9.0 occurred. When the great earthquake occurred, the HTTR had been stopped under the periodic inspection and maintenance of equipment and instrument. In the great earthquake, the maximum seismic acceleration observed at the HTTR exceeded the maximum value in seismic design. The visual inspection of HTTR facility was carried out for the seismic integrity conformation of HTTR. The seismic analysis was also carried out using the observed earthquake motion at HTTR site to confirm the integrity of HTTR. The concept of comprehensive integrity evaluation for the HTTR facility is divided into two parts. One is the “inspection of equipment and instrument”. The other is the “seismic response analysis” for the building structure, equipment and instrument using the observed earthquake. For the basic inspections of equipment and instrument were performed for all them related to the operation of reactor. The integrity of the facilities is confirmed by comparing the inspection results or the numerical results with their evaluation criteria. As the result of inspection of equipment and instrument and seismic response analysis, it was judged that there was no problem to operate the reactor, because there was no damage and performance deterioration, which affects the reactor operation. The integrity of HTTR was also supported by the several operations without reactor power in cold conditions of HTTR in 2011, 2013 and 2015.


2010 ◽  
Vol 102-104 ◽  
pp. 150-154
Author(s):  
Xiao Ping Hu ◽  
Xiao Ping Ye

The seismic load usually has a significant hazard to the safety of the tower equipment, so it’s important to execute of seismic design in engineering practice. In this paper, the time history analysis of the seismic response is carried out with the help of ANSYS software for the finite element model of the adsorption tower. Relevant time history data is obtained. Compared with seismic analysis of the current standard method, corresponding suggestions are given.


2021 ◽  
Vol 933 (1) ◽  
pp. 012009
Author(s):  
M A Rahman ◽  
M Teguh ◽  
F Saleh

Abstract Multi-story buildings are designed to withstand lateral forces against earthquakes. There are several ways to strengthen multi-story building structures. One way is to add a dual system, namely the shear wall or the bracing systems. Shear walls and bracing techniques can resist earthquake forces in vertical and horizontal directions that occur in building structures. This study compares the results of the structural analysis to three structural models. The 10- story of the structural response used in the research includes the story drift, base shear, displacement, and structural behavior due to the earthquake force. Model 1 is a general structure without the shear wall and bracing systems, Model 2 is a structure completed with L-shear walls, and Model 3 is a structure installed with the X-bracing system. The analyses of three Models were carried out by SAP2000 software. The results show that the slightest interstory drift occurs in Model 2, namely 0.041 mm. The decrease in deviation value that arises in Model 2 is 12.6 mm, with 34.35%. In Model 1, the story drift exceeds the allowable limit, so that with such a model, it is not feasible. Therefore, it is necessary to add shear walls or a bracing system.


2011 ◽  
Vol 255-260 ◽  
pp. 826-830 ◽  
Author(s):  
Nan Hong Ding ◽  
Li Xia Lin ◽  
Jia De Chen

Damping in double chains suspension bridge is non-uniform, which leads to coupled motion equations in main coordinate system. Based on the complex damping theory to solve equivalent viscous damping ratio used to describe energy dissipation characteristics of non-classical damping system approximately, a method is proposed to analyze seismic response of double chains suspension bridge considering non-classical damping modified by measured value. Influence of different damping forms on seismic response of double chains suspension bridge is analyzed, considering classical damping and non-classical damping respectively, through an example of double chains suspension bridge. The analysis shows that non-classical damping has significant effect on seismic response, and response based on the classical damping model is not reliable to double chains suspension bridge. Non-classical damping model should be used in seismic analysis of double chains suspension bridge, however, the seismic response of non-classical damping system under the longitudinal or vertical seismic wave can be substituted approximately by the seismic response calculated according to damping ratio of concrete tower and steel stiffening girder respectively, which can simplify the calculation during preliminary analysis.


2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
E. Tubaldi ◽  
A. Dall’Asta ◽  
L. Dezi

Partially isolated bridges are a particular class of bridges in which isolation bearings are placed only between the piers top and the deck whereas seismic stoppers restrain the transverse motion of the deck at the abutments. This paper proposes an analytical formulation for the seismic analysis of these bridges, modelled as beams with intermediate viscoelastic restraints whose properties describe the pier-isolator behaviour. Different techniques are developed for solving the seismic problem. The first technique employs the complex mode superposition method and provides an exact benchmark solution to the problem at hand. The two other simplified techniques are based on an approximation of the displacement field and are useful for preliminary assessment and design purposes. A realistic bridge is considered as case study and its seismic response under a set of ground motion records is analyzed. First, the complex mode superposition method is applied to study the characteristic features of the dynamic and seismic response of the system. A parametric analysis is carried out to evaluate the influence of support stiffness and damping on the seismic performance. Then, a comparison is made between the exact solution and the approximate solutions in order to evaluate the accuracy and suitability of the simplified analysis techniques for evaluating the seismic response of partially isolated bridges.


2020 ◽  
Vol 10 (5) ◽  
pp. 1819
Author(s):  
Pei Chi ◽  
Jun Dong ◽  
Wenlong Tian ◽  
Dafu Cao

The self-centering tension-only brace (SC-TOB) is a new and innovative bracing system that provides both a flag-shaped recentering hysteresis and load mitigation to structures. This paper presents an extensive investigation of the nonlinear seismic response of multistory steel frames built with SC-TOBs to internal force, drift, and energy dissipation. Pushover analysis subjected to two lateral load distributions and nonlinear dynamic analysis under ground motion ensembles corresponding to four hazard levels were conducted. The SC-TOBs can be designed to serve as conventional tension-only braces (TOBs) only providing lateral stiffness during minor earthquakes, to function with energy dissipation as intensity increases, and to fully recenter a structure even after severe earthquakes. The findings show that with an increase in the earthquake intensity, both the force response and drift response of the SC-TOB frames (SC-TOBFs) increased; however, the force distribution and drift distribution shapes of the SC-TOBFs remained almost constant. The SC-TOBFs generally experienced more energy dissipation in the lower parts of the building, while the upper stories dissipated almost no energy under certain load conditions, suggesting that the bracings on those stories could be replaced by conventional TOBs for economy. It is demonstrated that the SC-TOBs have immense potential to effectively improve seismic resilience to structures such that rehabilitation costs and operational disruptions after earthquakes are minimized.


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