| During the 40 years of reform and opening up,in the rapid development of civil engineering,a large number of existing buildings are facing the challenges of applicability and safety.According to Chinese national conditions,it is known that the external prestressing reinforcement technology is gradually becoming a panacea for solving the problems in this field.Compared with the traditional external prestressing method,External Prestress Structure of Tilted Belly Poles has the advantages of low cost,simple structure and convenient operation,and reducing the friction loss between the steering block and the prestressed reinforcement.The topic of this paper is "Research on seismic performance of reinforced concrete structures based on simply supported external prestressing technology" project(National Natural Science Foundation 51468040).The numerical simulation by ABAQUS finite element software.A three layer of two specimens of two span reinforced concrete structure,and the numerical simulation results were compared before and after reinforcement analysis.At the same time,setting up test model and in the laboratory,using numerical simulation method and experimental study on the combination of frame column frame under the beam reinforcement analysis.Research contents and main conclusions are as followings:(1)Establishing reinforced concrete frame model of finite by ABAQUS software as the first paragraph.The application of vertical load on the model,conduct numerical simulation;keep the vertical loading constant and inpose external prestressing for frame beams through cooling method.After reinforcing frame beam,conduct to numerica simulation caculation;compare and analysis before and after the reinforcement frame beam,the column stress performance change under vertical load.The conclusions are as followings:External prestressed reinforcement on the beam can reduce the longitudinal stress of frame column.Among,the decrement of column end is the most obvious.The horizontal displacement of the column end is caused by the prestressed reinforcement on frame beam.But the ranges of the horizontal displacement is increasing quickly with the increase of the number of the floors.When the floors are more,it can not be ignored.(2)When the the model of frame supporting vertical load,the same horizontal cyclic loading is applied to the frame structure before and after reinforcement.Respectively,conduct numerical simulation before and after framework model reinforcement.Compare and analysis the interaction of frame beam and colum under horizontal and vertical loads before and after frame beam reinforcement.To get stress performance change of frame column.The conclusions are as followings: The strengthening of frame beams by external prestressing can reduce the equivalent plastic strain of frame columns.It is bringing a negative effect on the edge column.The energy dissipation of the frame column is improved.But the amplitude is relatively small.The influence on the stiffness of the frame column is almost zero.(3)Construct a same scale reinforced concrete model of three layer,two specimens and two span in the laboratory as the numerical model.To applying vertical load for frame structure model,get the test results of reinforced concrete frame column stress performance under vertical load.Namely,With the external load growing,the longitudinal stress of each of column grow quickly.The increment speed of longitudinal reinforcement stress of the middle columes is faster than the side columes and corner columes.In addition,the external prestressing force is applied to the frame beam by the External Prestress Structure of Tilted Belly Poles.The longitudinal stress of the column decreases,when the external prestress increasing.The stress reduction of longitudinal reinforcement on the top and column bottom is higher than the 1/3-height and the 2/3-height of column.Reinforing for the beam promotes the stress in different parts of the column to the same values.These validate the correctness of numerical simulation. |
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