Numerical Simulation Study On The Mechanical Performance Of A New Type Of Adjustable Steel Buckling Restrained Brace

Since 1930,the number of high-rise and ultrahigh-rise buildings has gradually increased around the world.The World Trade Center,with a height of 411 meters,was built in New York in 1966.The Willis Tower,which has 412 meters tall and 110 stories,was built in Chicago in 1974.The sunshine 60 building,with a height of 226 meters and a total of 60 floors,was built in Ikebukuro,Japan in 1978.The Shanghai International Hotel,with 22 floors,was built in Shanghai in 1934.The Jinmao Tower,which has 420.5 meters tall,3 underground floors and 88 main floors,was built in Shanghai in 1998.In 2010,Guangzhou International Financial Center was completed,which located in Guangzhou,China.Its main tower has 440.75 meters,with 107 floors above ground and underground.In the same year,Zifeng building was put into use,which located in Nanjing,China,with a height of 450 meters,89 floors above the ground and 7 floors of podium.In 2016,Pingan International Financial Center was completed in Shenzhen,China,with a tower top height of 599.1 meters,a roof height of 592.5 meters,118 floors above the ground and 5 floors underground.Human beings are constantly breaking the record of building height,which is the proof of the continuous progress of their science and technology,is worthy to affirm.However,the increase of the height of the building also makes the seismic effect enhanced on it.Preventing high-rise and ultrahigh-rise buildings to collapse under rare earthquake,so as to provide a reliable guarantee for people's safety,has become the focus of attention for engineers and scholars all over the world.The idea of energy dissipation comes in this context.In general,the ordinary support will fail due to compression buckling under cyclic load.The buckling restrained brace can limit or prevent the buckling of ordinary steel brace,so as to make full use of the high tensile capacity of steel to dissipate seismic energy.A large number of tests have proved that the buckling restrained brace has excellent seismic performance.Based on the point,more and more buildings begin to use this new type of support instead of traditional support.In 2015,Tianjing 117 tower was capped,which has a height of 596.5 meters.This building uses the largest buckling restrained brace in China recently,with a single weight of 210 tons.The new type of steel adjustable buckling restrained brace belongs to one of the buckling restrained brace,which is made of steel and characterized by "adjustable".The "adjustable" means that to adjust the seismic performance of the buckling brace by changing the height of the T-shaped steel web.The "adjustable" will be the main line of analysis and research in this paper.The content of this paper is as follows:?1?Based on the design parameters of the test members,2 ordinary steel supports which named PYG_A1 and PYG_A2,4 new type of steel adjustable buckling restrained braces which named FQQ_A1^FQQ_A4,are established in ABAQUS.PYG_A1 and FQQ_A1 are consistent with the design parameters of the test members.The design parameters of others are obtained by changing the original design parameters.This paper introduces the finite element analysis software applied in civil engineering,explains the reason of using ABAQUS briefly,and describes the process of calculation and analysis of ABAQUS,such as modeling and analysis process,the unit system and model unit,geometric model and grid division,material and analysis steps,etc.?2?The test results of ordinary steel supports are given,and the test results,PYG_A1 and PYG_A2 finite element calculation results are analyzed and studied.The contents of analysis and research include that failure process and the failure location,the hysteretic curve and the skeleton curve,stiffness degradation characteristics,imbalance of tension and compression,capacity of energy consumption.The conclusions are as follows: 1)the failure position is generally about 1 / 2 along the support length;2)the hysteresis curve is asymmetric that the area around the curve in tension stage is much larger than that in compression stage;3)the skeleton curve is double fold line which is asymmetric;4)at the initial loading stage,the tensile capacity and compression capacity are approximately the same;5)at the middle and later loading stages,the compression capacity is obviously smaller than tensile capacity;6)under the same loading and elastic yield displacement ratio,the larger the slenderness ratio is,the energy dissipation capacity of the brace is.?3?This paper gives the test results of the new type of steel adjustable buckling restrained braces,and studies the results of test,FQQ_A1^FQQ_A4 finite element simulation.Compared with the ordinary steel support,the different content of the new type of steel adjustable buckling restrained brace is: the influence of T-shaped steel web height.The conclusions are as follows: 1)the failure position can be near the loading end of the support,or about 1 / 2 along the support length;2)the hysteresis curve is symmetrical with the coordinate origin as the center that the area around the curve in tension stage is approximately equal to the area in compression stage;3)the skeleton curve is double fold line which is symmetrical,the tensile bearing capacity and the compression bearing capacity is approximately the same;5)under the same loading and elastic yield displacement ratio,the larger the slenderness ratio is,the energy dissipation capacity of the brace is;6)T-shaped steel web height has an effect on energy dissipation capacity of the support,the energy dissipation capacity of the brace tends to be weakened with the decrease of the web height.Figure [55] table [26] reference [59]...