A Simplified Method to Calculate the Additional Interstory Drift of High-Rise Steel Frame Based on the P-Δ Effect

2020 ◽  
Vol 106 (sp1) ◽  
pp. 618
Author(s):  
Fengmei Pi ◽  
Wenjie Ren ◽  
Xinlei Yang ◽  
Gaotong Liu
Keyword(s):  
Steel Frame ◽  
High Rise ◽  
Interstory Drift ◽  
Simplified Method

Automation of seismic design of high-rise structure with braced steel frame

2021 ◽  
Author(s):  
Xin Zhao ◽  
Gang Wang ◽  
Jinlun Cai ◽  
Junchen Guo
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Structural Design ◽  
Structure Design ◽  
Steel Frame ◽  
Design Methods ◽  
Automatic Design ◽  
Component Level ◽  
Design Algorithm ◽  
High Rise

<p>With the continuous development and progress of society, the structure of high-rise buildings has been paid more and more attention by the engineering community. However, the existing high- rise structure design methods often have a lot of redundancy and have a lot of room for optimization. Most of the existing seismic design methods of high-rise structures are based on engineering experience and manual iterative methods, so that the efficiency of design can not meet the needs of the society. if the method of design automation is adopted, the workload of designers can be greatly reduced and the efficiency of structural design can be improved. Based on the digital modeling theory, this paper proposes a MAD automatic design algorithm, in which the designer provides the initial design of the structure, and the algorithm carries out the modeling, analysis, optimization and design of each stage of the structure, and finally obtains the optimal structure. The structural design module of this algorithm starts from the component level, when the component constraint design meets the limit requirements of the specification, it enters and completes the component constraint design and the global constraint design of the structure in turn. In this paper, taking a ten-story braced steel frame high-rise structure as an example, the optimal design is carried out, and its seismic performance is analyzed. the results show that the MAD automatic design algorithm can distribute the materials to each part reasonably, which can significantly improve the seismic performance of the structure and realize the effective seismic design.</p>

scholarly journals Shaking Table Test for Evaluating the Seismic Performance of Steel Frame Retrofitted by Buckling-Restrained Braces

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tingting Wang ◽  
Jianhua Shao ◽  
Chao Zhao ◽  
Wenjin Liu ◽  
Zhanguang Wang
Keyword(s):  
Seismic Performance ◽  
Shear Force ◽  
Seismic Waves ◽  
Shaking Table Test ◽  
Steel Frame ◽  
Shaking Table ◽  
Frame Structure ◽  
Acceleration Response ◽  
Buckling Restrained Brace ◽  
Interstory Drift

To investigate the seismic performance of buckling-restrained braces under the earthquake action, the shaking table test with a two-story 1/4 scale model is carried out for the ordinary pure steel frame and the buckling-restrained bracing steel frame with low-yield-point steel as the core plate. The failure modes, dynamic characteristics, acceleration response, interstory drift ratio, strain, shear force, and other mechanical properties of those two comparative structures subjected to different levels of seismic waves are mainly evaluated by the experiment. The test results show that under the action of seismic waves with different intensities, the apparent observations of damage occur in the pure frame structure, while no obvious or serious damage in the steel members of BRB structure is observed. With the increase in loading peak acceleration for the earthquake waves, the natural frequency of both structures gradually decreases and the damping ratio gradually increases. At the end of the test, the stiffness degradation rate of the pure frame structure is 11.2%, while that of the buckling-restrained bracing steel frame structure is only 5.4%. The acceleration response of the buckling-restrained bracing steel frame is smaller than that of the pure steel frame, and the acceleration amplification factor at the second story is larger than that at the first story for both structures. The average interstory drift ratios are, respectively, 1/847 and 1/238 for the pure steel frame under the frequent earthquake and rare earthquake and are 1/3000 and 1/314 for the buckling-restrained bracing steel frame, which reveals that the reduction rate of lateral displacement reaches a maximum of 71.71% after the installation of buckling-restrained brace in the pure steel frame. The strain values at each measuring point of the structural beam and column gradually increase with the increase of the peak seismic acceleration, but the strain values of the pure steel frame are significantly larger than those of the buckling-restrained bracing steel frame, which indicates that the buckling-restrained brace as the first seismic line of defense in the structure can dramatically protect the significant structural members. The maximum shear force at each floor of the structure decreases with the increase in height, and the shear response of the pure frame is apparently higher than that of the buckling-restrained bracing structure.

Re-examination of steel frame office buildings in preventing collapse when subject to intense fires

2018 ◽  
Vol 4 (3) ◽  
pp. 82
Author(s):  
Robert Mathews Korol ◽  
Ken S. Sivakumaran ◽  
Paul Heerema
Keyword(s):  
Kinetic Energy ◽  
Steel Frame ◽  
Building Construction ◽  
Newtonian Mechanics ◽  
Normal Concrete ◽  
Vast Array ◽  
Concrete Floor ◽  
High Rise ◽  
Floor Slabs ◽  
Extreme Fire

The purpose of the paper is to investigate the extent to which present-day design of steel framed buildings is susceptible to total collapse when subjected to extreme fire events. We select a 50 storey structure in which 2 and 4 adjacent storeys located at different above-ground heights are, in separate scenarios engulfed in raging fires. A total of 8 scenarios are analyzed, employing Newtonian mechanics and realistic energy dissipating properties of H-shaped columns and normal concrete floor slabs possessing secondary (shrinkage and temperature) reinforcement alone. While the present Canadian building code is the basis for our column designs, other standards provide very similar specifications. Although fire proofing is required in virtually all high rise building construction, we are excluding such materials in order to simplify the analyses, but clearly do not advocate its omission – quite the opposite in fact. As well, attributes such as floor beams, partitions and furnishings of every description, all of which would in practice participate in absorbing the kinetic energy of a crush-down upper block are excluded. Despite such a vast array of conservative assumptions, it is shown that partial collapse may occur during crush-down, however, in no case will total collapse be the consequence. These results should provide some comfort to code writers that their requirements should indeed prevent the most catastrophic of failures due to fires.

Numerical Simulation on the Overall Dynamic Response of One High-Rise Steel Frame

2012 ◽  
Vol 204-208 ◽  
pp. 1215-1219
Author(s):  
Dai Guo Chen ◽  
Yong Yao ◽  
Hai Jun Wang ◽  
Yong Jun Deng ◽  
Jing Zhou
Keyword(s):  
Dynamic Response ◽  
Spectrum Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Steel Frame ◽  
Mode Analysis ◽  
Seismic Action ◽  
Modal Shape ◽  
High Rise ◽  
History Analysis

Using the finite element analysis software ANSYS to analyze the overall dynamic response of one specific high-rise steel-frame,including modal analysis, spectrum analysis and time-history analysis. Then do a comparative analysis with the results of calculation by the professional software PKPM. As the results: the structural calculation can use layer model; Larger mutations appeared in the stress of weak-story and the relevant story need to reinforce or set up supports under the anti-seismic design in the elastic time-history analysis of structure; Y-direction translation is preferentially happened in first order modal shape and lateral-torsional coupling happened in third order modal shape among the vibration mode analysis; The response spectrum analysis of frequent earthquake show that seismic action is more serious in ground layer.

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