| Nowadays,due to the shortage of housing resources,compared with the traditional construction methods,it is difficult to build a house.The construction of prefabricated buildings is far ahead of the traditional construction methods in terms of efficiency and quality;The promotion of prefabricated buildings can make it possible in the shortest possible time,The fastest and most efficient way to reduce the pressure of housing resources.Prefabricated buildings have become a new building mode vigorously promoted by the construction industry.It has many advantages,such as simple and fast construction,excellent bearing capacity,short construction period and so on.Therefore,the research of assembly has become a hot topic in the construction industry;The main difficulty in the design and construction of prefabricated buildings lies in the design of nodes.All kinds of connection nodes are the key of assembly building structure splicing.The design of joints is too complicated,which has great resistance to the installation and construction on the spot;Defects in joint design will lead to insufficient bearing capacity.Danger occurs in natural disasters such as earthquakes.Compared with the traditional cast-in-place structure,Stress concentration is easy to occur at the joints of prefabricated structures.The node is also the first object to be destroyed,and the assembly node problem is the main direction of assembly research at present.In this paper,a new type of fabricated beam-column connection is proposed.The beam and column are connected through eight bolts through the reserved holes of the beam and the T-shaped beam is selected.The positions of the two flanges are reserved holes.Two groups of specimens were made in this experiment.High strength bolts and ordinary bolts were used as comparative tests.Two Groups of tests were carried out to study the plastic failure of beams and columns under low cyclic loading.The plastic deformation of high strength bolts is larger than that of ordinary bolts.However,the ultimate bearing capacity and seismic capacity are weaker than those of high-strength bolts;The hysteretic behavior of the beam-column joint is analyzed,and the skeleton curve is analyzed.Bearing capacity degradation analysis,joint core area strain analysis and ductility analysis.Before the low cyclic loading test is carried out,The finite element analysis software abaqus is used to simulate the experimental model.In order to ensure the accuracy of numerical simulation,each group of bolts uses a variety of models as samples.Two groups of models are used to build the whole model and separate model respectively,which are tested in the fabricated concrete beam-column joints.A more accurate computational model can be obtained by using discrete modeling.Through the experiment and numerical simulation,the following conclusions are obtained:(1)The seismic performance of the new assembled beam-column joints meets the design requirements.During the test,the concrete of the flange was crushed and destroyed;The bolt is the main force part of the component,The bolts were deformed to varying degrees,and the concrete at the bearing steel plate was cracked,but the overall structure remained stable.There is no damage to the corbel of beam-column connection and the non-joint core area of column body.(2)The Plastic deformation of the high-strength bolts of the fabricated joints is small because the grade of the bolts is too large.The concrete in the core area of beam-column joints is shear damaged,and the high-strength bolts are due to their own strength.The ultimate bearing capacity of the whole member is higher than that of the ordinary bolt group.(3)By Comparing the test results of high strength bolts and common bolts,it is found that the rotational stiffness of high strength bolts is higher than that of common bolts.The rotation angle is smaller than that of ordinary bolts,but both groups of bolts show good rotation ability.The ductility of high strength bolts is lower than that of ordinary bolts.With the increase of load,the strength of ordinary bolts is lower than that of high-strength bolts.The bolts were destroyed before the concrete,and one of the eight bolts was found to be broken after the test;It is recommended to use 8.Class 8bolt.(4)The New assembled beam-column joint has good energy dissipation performance under seismic load.The simulation results are in good agreement with the test results,and the component design meets the requirements of strong columns and weak beams.The content of this paper can provide a reference for the application of fabricated beam-column joints.Once again,Thanks to the national key R & D project funding fund number(2016YFC0701500)to provide strong support and help for this experiment。Figure 76 table 11 reference 65... |
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