Finite Element Study On The Mechanical Behavior Of The Tongue-and-groove Connection Area Of The Assembled Frame Beam

With the industrial upgrading and structural adjustment of the construction industry,the precast concrete structure has become the focus and breakthrough of the development of construction industrialization.At present,the prefabricated frame structure has disadvantages such as complex construction,weak integrity and poor reliability in earthquake.Under the development trend of building structure towards efficient construction,the prefabricated frame structure needs to be further improved.The new type of prefabricated frame joints presented in this paper are mainly composed of two parts,namely,the blind leg and the prefabricated notched beam,and are connected by the connecting cover plate fixed with high strength bolts and the post-poured laminated concrete.The main research contents and results are as follows:(1)The low-cyclic cyclic loading test was carried out on four assembled specimens(one cast-in-place joint and three assembled joints),and the failure modes and seismic performance indexes were systematically analyzed.The data show that the tongue-and-groove joint used in the test can meet the general design needs,but its structure needs to be improved to some extent.The failure area of the whole casting specimen is mainly concentrated at the end of the beam,while the failure area of the assembled specimen is mainly concentrated at the top of the beam after casting laminated layer area and the dark leg area,which can realize the purpose of plastic hinge outward,and the main connecting parts(bolts and steel plates)have reliable force transmission.(2)The finite element model of the prefabricated tongue-groove connection area was established by using the finite element software ABAQUS,and the failure modes,hysteretic curves and skeleton curves obtained from the simulation were compared with the test results.It can be considered that the finite element model can truly reflect the material properties,force transmission characteristics and seismic performance of the assembled specimen.(3)After the correctness of the finite element model is verified,the parameter expansion analysis is carried out,and the influence of each parameter on the seismic performance is studied respectively.Both the thickness of the side connection cover plate and the bottom connection cover plate have improved the seismic performance,and the thickness of the side connection cover plate has improved the seismic performance more obviously.The bolt arrangement of the initial specimen TGA-B2 can best meet the requirements of economic type and seismic performance at the same time,and the ductility can be improved to some extent by increasing the strength grade of concrete in the post-cast laminated layer area and the thickness of the side connection cover plate.Through variable parameter analysis,the peak bearing capacity of the prefabricated specimens reached or even exceeded that of the cast-in-place specimens,but the ductility and energy dissipation capacity of the prefabricated specimens were lower than those of the cast-in-place specimens.Through the above experimental research and computer simulation analysis,the seismic performance of the assembled tongue-and-groove connection area has been studied in depth,some test data and calculation results have been obtained,and a more accurate assembly finite element model has been established,which lays a foundation for the research and application of this type of assembly joints.