Seismic Performance Of Dry-connected Assembled RC Frame T-beam-column Joints

The construction industry is one of the important growth sources of the national economy.In recent years,in order to improve the production efficiency of the construction industry and realize green and sustainable development,the state has issued many policies to promote the prefabricated building structure system and comprehensively carry out the structural adjustment and industrial upgrading of the construction industry.Dry method connection is one of the main connection forms of prefabricated concrete structures,which can give full play to the advantages of prefabricated buildings to the greatest extent.It has the advantages of fast construction speed,labor saving,green environmental protection and little environmental impact.It is a model vigorously promoted in the current prefabricated construction industry.Therefore,it has become one of the hot research directions of the current fabricated structure.Therefore,a new type of fabricated T-shaped beam column joint with all dry connection is proposed in this paper,and the composition and structure of the joint are defined.For this joint,the low cycle cyclic loading test and numerical simulation analysis are carried out,and the failure mode,stress distribution characteristics,energy dissipation performance and stiffness degradation characteristics of the joint are analyzed.Then,based on the finite element model,the parameter analysis is carried out to clarify the impact of different geometry and connection methods on the seismic performance of the joint.Based on this,the performance design method of the new dry method beam column joint is established,and the corresponding design process is established.The main research contents of this paper are as follows:1.This paper summarizes the development and current situation of dry joint connection technology of prefabricated frame structures at home and abroad,analyzes the existing problems,and puts forward the method of replacing the core area of beams and columns with section steel and splicing the beam ends with plywood through the comparison of seismic performance and construction convenience.(Chapter 1).2.The composition and structural ideas of the new dry beam-column joint were clarified,the connection form of each component was studied,the geometric dimensions of each component were determined in combination with the actual project,the force transmission path and force mechanism of the joint were analyzed.and the static mechanical analysis and mechanical performance checking calculation of the joint were carried out(Chapter 2).3.The low cycle reciprocating loading test of the joint was carried out.A 1:2 new dry method beam-column joint scale model and a cast-in-place joint model were designed and fabricated,and the pseudo static loading tests were carried out respectively,and the failure modes,hysteresis curves and energy dissipation performance,stiffness degradation and ductility of the two joints were analyzed.The results show that the bearing capacity of the new dry method beam-column joint is basically the same as that of the cast-in-place joint.Due to the slippage of the bolt,the hysteresis curve is not full enough,and the energy dissipation capacity is slightly weaker than that of the cast-in-place joint,but the ductility and stiffness degradation rates are both better than the cast-in-place joint.In general,the seismic performance of the new dry method beam-column joint is similar to that of the cast-in-place joint(Chapter 3).4.The refined finite element model is established by ADINA,and the test is inverted.The failure mode,stress distribution,hysteresis curve,energy dissipation performance,stiffness degradation and ductility of the test and finite element analysis are compared.The results show that the crack development,stress distribution,load eigenvalues,stiffness degradation and ductility coefficient of the joints are basically consistent with the experimental results,and the skeleton curve error is less than 6%(Chapter 4).5.Taking the thickness of flange splice splint,steel surface treatment,splice position and screw hole form as parameters,single-parameter analysis was carried out on the seismic performance of the joint,and the influence of different parameters on the seismic performance of the new dry beam-column joint was analyzed,then puts forward the performance design method of the new dry method beam column joint,and establishes the corresponding design process,which provides a design reference basis for practical engineering application(Chapter 5).