Experimental Study And Theoretical Analysis On Seismic Behavior Of Column Joints In Hybrid Dry Frame

The traditional construction method of reinforced concrete structure is usually cast-in-place integral type.All members are supported by formwork on site,cast-in-place concrete and maintained on site.It has the advantages of strong integrity,high rigidity,good seismic performance and impact resistance.But at present,with the aging of the population,the labor resources are increasingly tense,but the operation mode is mainly wet operation,the construction process is complex,the construction cycle is long,and the construction operation is chaotic.The traditional wet construction method will be difficult to maintain for a long time.Compared with the traditional cast-in-place construction,prefabricated construction has obvious advantages.In the new development opportunity,the new prefabricated buildings with components manufactured well in the factory and other prefabrication sites,which only need to complete assembly and a small amount of wet work on site,high production efficiency,good construction environment,easy to control component quality and conducive to sustainable development will become an important development direction of construction engineering,and at the same time,develop a new type of buildings with excellent comprehensive performance and easy to promote Assembly structure system has become the current development requirements.At present,the research on the new type of RCS connection composite frame structure is just in its infancy.Based on the existing research results of the traditional RCS concrete column steel beam joints,there is still a lot of work to be done on the mechanical properties of the new type of RCS connection composite frame joints.In this paper,the mechanical properties of column joints in a new type of RCS connected composite frame are analyzed by means of one-way static load test and finite element simulation.The specific work is as follows:(1)the research status and application of top and bottom angle steel connection structure system in the construction of RCS hybrid structure and semi-rigid joint are summarized,and the top and bottom angle steel connection structure system with ribs is analyzed The structure and advantages of the column joints in the prefabricated concrete column steel beam frame with angle steel are introduced in detail.(2)In this paper,the quasi-static loading test of four new-type RCS connected composite frame column joints is carried out,the deformation characteristics and stress changes of the joint specimens in the whole test process are observed,four cross beam column joints in the middle of the frame are designed and manufactured,and the quasi-static test research is completed,and the section size of beam column,the number of bolts at beam end and the size of angle steel are analyzed The influence of other factors on the seismic performance indexes such as bearing capacity,failure mode and ductility energy consumption.The strain distribution law of the key section of the joint beam column surface is obtained,and the load displacement curve,the skeleton curve and the cumulative energy dissipation capacity of each specimen under the one-way load are drawn.(3)Using ABAQUS general finite element software,the finite element numerical simulation of the new RCS hybrid joint is studied.The parameters involved in the modeling process of ABAQUS,the material constitutive relationship of concrete and steel,the setting of contact,the division of mesh and the determination of boundary conditions are introduced in detail.The failure mode,deformation form and stress of the new RCS hybrid joint are completed And the analysis of Concrete Damage Cracking and other angles,and the analysis results are compared with the test results.On the basis of verifying the reasonable parameter setting of the model,the parametric analysis of the influencing factors of the five main factors of concrete column axial compression ratio,concrete strength,stirrup area,stirrup spacing and stirrup strength has been completed with SJ-2 and SJ-4 as the reference members.On the basis of SJ-2,the paper studies the increase of angle steel size and the change of steel on the basis of no slip of beam end bolt The influence of the beam height on the bearing capacity of the joint is analyzed.(4)Based on the diagonal member truss model,this chapter further analyzes the load transfer path and failure mode of the joints,analyzes the shear bearing capacity of the core area and puts forward the corresponding bearing capacity calculation formula.The effective calculation height of the core area is determined by referring to the finite element analysis results and the European Code.The calculation model of shear capacity in the core area considering the influence of axial pressure is established,and the calculation formula of shear capacity in the core area of the prefabricated concrete column steel beam middle column joint with rib top and bottom angle steel is put forward.The calculation method of the formula is verified by the completed test data and the results of finite element parameterization.