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

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.

Author(s):  
Yuko SHIMADA ◽  
Motoki AKAZAWA ◽  
Yosuke ITO ◽  
Yuichi MATSUOKA ◽  
Satoshi YAMADA ◽  
...  

2011 ◽  
Vol 243-249 ◽  
pp. 1425-1428 ◽  
Author(s):  
Ming Ji Fang

The shaking table test of a full-scale steel frame structure with ALC external wall panels is performed in this paper. Based on the experimental results, the seismic behaviors of ALC external walls and joints are studied, such as the destruction properties of ALC external walls and joints and the effects of external walls on the dynamic properties of steel frame. Several useful conclusions and suggestions are presented in the paper.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Shi Yan ◽  
Jian Niu ◽  
Peng Mao ◽  
Gangbing Song ◽  
Wei Wang

Mechanical properties of shape memory alloy (SMA) wires were experimentally researched in this paper, and an energy dissipater made of SMA wire cable was designed and applied in a steel frame structure model by using superelasticity characteristics of SMAs to passively reduce dynamic responses of the steel frame structure under seismic load. For the characteristics of large relative displacements between the stories of the steel frame structure on both diagonal ends and the consideration of initial prestrain effects of the SMA cables, three kinds of the whole control, the part control, and no control of the shaking table tests and numerical simulations were carried, respectively. Through the results of the shaking table test and numerical simulation analysis, the dynamic responses such as the maximum displacement, velocity, and acceleration at the top layer of the steel frame structure applied with SMA cables are significantly decreased compared with the no control case. However, considering the premise of both effectiveness and efficiency, the part control effect is superior to the whole control. In many cases, it can meet the control requirement of reducing the maximum displacement and acceleration, while the superelasticity of SMAs can be sufficiently played, realizing the passive control purposes of the steel frame structure based on the energy dispassion through the application of the SMA cables. The proposed method has broad application prospects in the passive control field of building structures.


2013 ◽  
Vol 454 ◽  
pp. 204-208
Author(s):  
Hong Biao Liu ◽  
Qiang Zhang ◽  
Xian Peng Liu

The accurate sine-swept function is proposed by theoretic derivation. The natural frequencies of five-story steel frame structure in transverse direction were identified by modal test. Based on the numerical simulation results of steel frame structure excited by sine-swept vibration, it is proved that the difference of structural response between forward excitation and backward excitation is little,and both the results of them can be used to evaluate the dynamic property of structure. However, it is proper to decide whether the response results of structure should be modified or not based on the dynamic properties of table-board. The conclusions above can provide basis for design and dynamic time-domain analysis of shaking table test in sine-swept excitation.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247557
Author(s):  
Shuai Huang ◽  
Yuejun Lyu ◽  
Liwei Xiu ◽  
Haijun Sha

Sea ice is one of the main loads acting on a wind turbine tower in areas prone to icing, and this threatens safe working life of the wind turbine tower. In our study, a simplified calculated model of ice, wind turbine tower, and water dynamic interaction under earthquake action was proposed, which could avoid to solve a large number of nonlinear equations. Then, the seismic behaviour of the wind turbine tower with and without the influence of sea ice was investigated, and we found that the influence of the greater mass of the sea ice on the seismic response of a wind turbine tower should be considered when the wind turbine tower is designed in an area with thick ice. With the influence of the most unfavourable ice mass, the deformation and energy dissipation capacity of the wind turbine tower are decreased, and the wall thickness or stiffening rib thickness should be increased to improve the seismic performance and ductility of the wind turbine tower; the shear force and bending moment increased significantly on the wind turbine tower, and the shear force changes at the bottom of the wind turbine tower and position of action of the sea ice: attention should be paid to the wind turbine tower design at these positions. Finally, we conducted the shaking table test, and verified the rationality of our proposed simplified model.


2019 ◽  
Vol 13 (03n04) ◽  
pp. 1940004 ◽  
Author(s):  
Dongsheng Du ◽  
Shuguang Wang ◽  
Weiwei Li ◽  
Feng Xu ◽  
Weiqing Liu

A series of shaking table tests were performed to investigate the seismic behavior of the pre-fabricated steel frame structure infilled with autoclaved aerated concrete (AAC) external wall panels. The reliability of a new type of joint connections adopted in the structure between the steel frame and the wall panels was particularly validated during the test. Dynamic tests were carried out on a two-story full-scaled steel frame, considering seismic loading of three earthquake waves with different imposed peak accelerations in the range of 70[Formula: see text]cm/s2 to 400[Formula: see text]cm/s2. The experimental analyses encompassed cracking patterns, failure mechanisms, dynamic property and seismic response of the structure. The results show that the structural components, including the joint connections between the steel frame and the walls, behaved well even under the rare earthquake at 8∘. The structural stiffness of the steel frame infilled with wall panels was increased by 56%, compared with the steel frame infilled without wall panels. The damping ratio of the undamaged steel frame installed with wall panels was 7.25%.


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