The Seismic Performance Analysis of Light Steel Story-Adding on Steel Frame

2014 ◽  
Vol 501-504 ◽  
pp. 1573-1579
Author(s):  
Hao Chen ◽  
Jiu Ping Wei ◽  
Tian Wang ◽  
Ting Ting Ma
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Damping Ratio ◽  
Great Influence ◽  
Steel Structure ◽  
Steel Frame ◽  
Frame Structure ◽  
Irregular Structure ◽  
Holistic Analysis ◽  
Layer Steel

It is common for using light steel structure as an upper layer to alter the multi-layer frame structure. But it is easy to form vertical irregular structure of rigid upper and flexible bottom. And the mass, stiffness, period and damping ratio are change after layer-adding. So it should take a holistic analysis of the structure. By using sap2000 to simulate a two-layer steel frame with a portal frame added, the seismic performance was analyzed. The result shows: transfer floor was relatively weak, it requires attention when seismic design; damping ratio has a great influence to seismic, it should been chose reasonably.

Dynamic Analysis of Concrete Frame Structure with Story-Adding Steel Structure at the Top

2015 ◽  
Vol 744-746 ◽  
pp. 65-70
Author(s):  
Xiang Hong Sun ◽  
Lie Ping Xie ◽  
Feng Ji
Keyword(s):  
Seismic Performance ◽  
Damping Ratio ◽  
Steel Structure ◽  
Steel Structures ◽  
Frame Structure ◽  
Natural Period ◽  
Concrete Frame ◽  
Finite Element Software ◽  
Original Frame ◽  
Whiplash Effect

After steel structure was added on top of a concrete frame structure, the mass, stiffness, natural period and damping ratio of the original frame structure has changed significantly. Using finite element software ANSYS and software PKPM respectively, model of the original frame structure and the new structure with story-adding steel structure were built. Furthermore, seismic performance of the three structures was studied. Weak location of the structure was found out. Finally, the main factors were analyzed. Results show that whiplash effect is not obvious when one-story steel structure was added on the top of the original frame structure. Also, seismic performance of the frame structure with two-story steel structures on the top is perfect. Some suggestions are put forward for designing the similar structure.

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>

The Design Review and Optimization of the Special-Shaped Steel Frame Structure

2010 ◽  
Vol 163-167 ◽  
pp. 600-604
Author(s):  
Ke Dong Tang ◽  
Jian Fu ◽  
Jun Dai ◽  
Peng Zhang ◽  
Rui Feng Yu
Keyword(s):  
Circulating Fluidized Bed ◽  
Reference Value ◽  
Steel Structure ◽  
Steel Frame ◽  
Frame Structure ◽  
Boiler Steel ◽  
Element Analysis ◽  
Structure Reliability ◽  
Calculation Results ◽  
Steel Frame Structure

According to the finite element analysis of a circulating fluidized bed boiler steel frame structure, the essay concludes to the calculation results of the main steel structure, moreover the structure and the composition of bars are adjusted and optimized which improve the safety of the structure reliability and reduce the volume of steel. All of the above contents have certain reference value on the similar structure.

Displacement-Based Seismic Design Method of Steel Moment Frame

2012 ◽  
Vol 166-169 ◽  
pp. 640-644
Author(s):  
Qian Zhang ◽  
Ya Feng Yue ◽  
Ergang Xiong
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Steel Frame ◽  
Frame Structure ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Displacement Based ◽  
Seismic Design Method ◽  
Steel Frame Structure ◽  
Displacement Based Seismic Design

According to lots of documents previously studied, a seismic design method is put forward based on displacement for steel moment frame. This method is established in condition that the yield displacement of steel frame can be determined by its geometrical dimension; then the objective displacement (ultimate displacement) can be determined in light of performance level of the structure, and the corresponding coefficient of ductility can be obtained. Thereafter, the design base shear of steel frame structure can be calculated by the use of reduced elastic spectrum. Thus, the design of stiffness and capacity can be conducted on steel frame structure. The analysis of case study indicates that the displacement-based seismic design method addressed herein is of reasonable safety and reliability, and of operational convenience, which can still realize the seismic design of steel frame structure at different performance levels.

Influence of member geometric imperfection on geometrically nonlinear buckling and seismic performance of suspen-dome structures

2014 ◽  
Vol 14 (03) ◽  
pp. 1350070 ◽  
Author(s):  
Z. Zhou ◽  
J. Wu ◽  
S. Meng
Keyword(s):  
Critical Load ◽  
Seismic Performance ◽  
Seismic Analysis ◽  
Great Influence ◽  
Steel Structure ◽  
Analysis Method ◽  
Initial State ◽  
Nonlinear Buckling ◽  
Finite Element Program ◽  
Geometric Imperfection

This paper focuses on the effect of member geometric imperfection on nonlinear geometrically buckling and seismic performance of a new style of space steel structure, suspen-dome, which is composed of a reticulated shell and cable-strut system. By supposing the initial curvature of members as half-wave sinusoids, a stiffness equation of imperfect truss elements is derived for the struts, while that of imperfect beam elements is derived for the reticulated shell members. The proposed imperfect elements are implanted into ANSYS finite element program. Three numerical examples are employed to validate the proposed imperfect elements and analysis method. An ellipsoidal suspen-dome of Changzhou gymnasium is taken as an example. The results show that the imperfection value has relatively great influence on the structural stiffness. With the increase of member imperfection, the critical load decreases in a basically linear way. Under different prestress states, the relation curves between the critical load and imperfection are basically parallel. The nonlinear seismic analysis results show that when imperfection is included, the initial state responses are different, namely, the seismic displacement increases while the stress in rods and cables decreases. The proposed imperfection analysis method can be widely used in not only suspen-dome structures, but also other kinds of prestressed space grid structures. In this way, the influence of member imperfection on structural buckling and seismic performance can be estimated.

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.

scholarly journals Coupling Ratio-Based Design and Seismic Performance of Modular Prefabricated Hybrid Coupled Walls

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Yun Shi ◽  
Yumin Zhang ◽  
Jianbo Dai ◽  
Guangyuan Weng
Keyword(s):  
Finite Element ◽  
Seismic Performance ◽  
Seismic Design ◽  
Structural Damage ◽  
Design Procedure ◽  
Steel Structure ◽  
Design Stage ◽  
Lateral Stiffness ◽  
Coupling Ratio ◽  
Element Analysis

Based on the advantages of modular prefabricated multistory steel structure, a full-bolt-connected modular steel coupling beam-hybrid coupled wall system is presented. Further, a method of estimating the coupling ratio (CR) is proposed according to the continuous link method. A CR-based seismic design procedure is determined such that the structure utilizes the lateral stiffness of the shear wall, which is necessary to avoid structural damage under frequently occurring earthquakes. However, it also exhibits excellent ductility of the coupling beams, which is necessary for dissipating energy under infrequent earthquakes. Subsequently, nonlinear hysteretic analyses are conducted from finite element analysis software ABAQUS, and a parametric study based on the finite element technique is performed to identify the optimal value of the coupling ratio. Results indicate that the seismic performance of modular prefabricated HCWs was excellent, and the basic requirements for ductile behavior and lateral stiffness were satisfied for CR values from 50% to 60%. The obtained results confirm the accuracy of the CR-based seismic design method proposed in this study and are supported by the selection of the design parameter at the initial design stage.

Effect of Connection Deficiency on Seismic Performance of Precast Concrete Shear Wall-Frame Structures

2019 ◽  
Vol 13 (03n04) ◽  
pp. 1940005 ◽  
Author(s):  
Zijian Cao ◽  
Quanwang Li
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Precast Concrete ◽  
Shear Wall ◽  
Frame Structure ◽  
Occurrence Rate ◽  
Point Estimate ◽  
Seismic Reliability ◽  
Point Estimate Method ◽  
Seismic Design Code

The quality of precast concrete (PC) component connections is one of the main factors that affect the seismic reliability of PC structures. China is developing PC structures in high seismic regions, and it is important to assess the effect of connection deficiency on seismic performance of PC structures. This paper presents a comprehensive method to assess the seismic reliability of PC shear wall-frame structure whose wall panels are assembled through grouted sleeve connections which are susceptible to insufficient grouting. Considering the uncertainties associated with the number, locations and loading behavior of defected sleeve connections, the probabilistic behavior of PC shear wall with defected connections is estimated through point estimate method using simulation results of the experiment-validated finite element model. Then, a simple shear wall-frame building, designed for the seismic intensity of 8 according to China’s seismic design code, is modeled on platform of OpenSees. Static pushover analyses and seismic fragility analyses are performed on the structure with different degrees of connection deficiency, to investigate the effect of deficiency occurrence rate on seismic performance. The seismic performance is significantly affected by connection deficiencies; it no longer meets the requirement of seismic design as the deficiency occurrence rate exceeds 25%, so the occurrence rate of defected connections should be controlled carefully in construction site.

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