| Electricity,communications,water supply,large-scale medical systems and some other lifeline projects,as well as national defense,military,marine and some other security projects played an important role in social and economic development.These major projects not only require sufficient safety and reliability before the earthquake and when the earthquake occurred,but also need to maintain their normal function in a certain extent after the earthquake.At present,the seismic design of structure aim to improve the plastic deformation of materials to obtain the ductility structures which have good energy dissipation capacity.This ideology ignores the structure's use function and recoverability after the earthquake,though it can improve the seismic capacity of the structure.Meantime,the excessive deformation of structures produced after the earthquake may affect its normal use function.In this paper,a new kind of recoverable C-shaped shell structure column is proposed,which has the advantages of light weight,high strength,simple structure and stable structure.And it has a certain self-reset function without using pre-stressed steel.In this paper,the following studies were carried out for this new type of column.(1)Finite element software is used to simulate and analyze the flexural buckling and recovery performance of C shaped tape spring,The results showed that the structure has stable structure and good recovery different,C-shaped steel column shell scale models which has different connection form were compared,results showed that this kinds of steel column had good recovery performance,high load ratio,it is simple and stable structure.Besides,semi rigid connection form was more stable than fixed connection.(2)The existing 65 manganese spring steel plates on the market were processed,and the heat treatment process of the C-shaped shell plate was explored.The heat treatment process This paper summarized a set of heat treatment process suitable for the shell,the two heat treatment process was controlled by different temperature: the first heat treatment eliminated the mechanical stress,maintain the size and the shape of plate;the second heat treatment improved the metal internal organizational structure,enhanced the hardness and elasticity.(3)The axial compression tests were carried out for 4 groups of new columns with different thickNess.These columns had stronger recovery performance and ultimate bearing capacity,higher energy dissipation capacity after twice heat treatments.Results showed the new structure could be used for the rapid recovery after the earthquake.The ultimate bearing capacity of each specimen and its decay rate were also given in this paper.The specimen,its thick was 1.5mm,with relatively limited bearing capacity,its deflection value under the limit load was given.The experimental results showed that the bearing capacity of this new type of recoverable structure decreased slowly with the rapid increase of deflection.(4)The new C-shaped cylindrical shell structure column were simulated and analyzed using finite element analysis software ABQUS,test results and simulation results were in good agreement.Analysis indicated that finite element analysis model simulated the structure of axial compression property is reliability,Based on the experimental data and the finite element simulation,the theoretical formula for calculating the ultimate bearing capacity of the new recoverable C shaped steel column is obtained. |
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