Research On Design Method And Seismic Performance Of The New Type Section Steel Concrete Beam-Section Steel Concrete Column Node And Framework

Steel reinforced concrete compared with the ordinary reinforced concrete structure has obvious advantages:high bearing capacity,stiffness big,smaller relative section,good ductility and energy dissipation ability is stronger,and so on,these advantages make it get better application in the high-rise frame structure.Force complex steel reinforced concrete beam—column joints,and the cohesive force of steel and concrete is small,easy to produce the bond—slip damage,the development of shear fracture under repeated load node to node failure,early to solve these problems,this paper puts forward the new braced steel reinforced concrete beam—section steel concrete column frame node structure,and through theoretical study,model test and numerical method for the new steel encased concrete node and framework for seismic performance research.The main work is as follows:(1)put forward new truss type steel reinforced concrete beam—section steel concrete column node,in section size,the size of the Angle,axial compression ratio three parameters as design parameters,to study the ultimate bearing capacity of node as the goal,according to the structure of the frame structure joints and mechanical characteristics design and production of six standard layer nodes and the top six nodes in a total of 12 specimens,low reversed cyclic loading tests are carried out.The fracture development law,failure mode,stress characteristics,skeleton curve,bearing capacity,strength degradation and ductility performance of new steel bone concrete joints under test load are studied.Considering the section size,size of abdominal rod and axial compression ratio of the three design parameters on the seismic performance and the effect of it is concluded that under certain conditions,section size and the increase of size of abdominal rod can improve the seismic performance of structure,and the structure of the axial compression ratio increases the ductility and energy dissipation performance slightly lower,little influence on the degradation of bearing capacity of node.(2)In order to further study under repeated load braced steel reinforced concrete beam—section steel concrete column frame structure of the nodes in the overall structure of the energy dissipation mechanism,failure pattern,ductility and hysteretic performance,design and production of the 2 large scaled frame model,and pseudo static load test,the overall seismic performance research framework.Through the pseudo static test process of new steel reinforced concrete frame cracks crack and development centre sill,column node,failure pattern,load—displacement curve analysis framework of the structure of the skeleton curve,ductility,energy dissipation performance,strength degradation and stiffness degradation,etc.,it is concluded that the truss type steel encased concrete beams—section steel concrete column frame structure has good performance and energy consumption steel content can be appropriately increasing the displacement ductility coefficient of structures,content of steel framework bearing capacity of large drops slowly.(3)Based on new type braced steel reinforced concrete beam,steel concrete column specimens test result,established the new steel encased concrete nodes(standard layer nodes and the top of the restoring force model),including the model of skeleton curve based on calculation,stiffness degradation rule and hysteresis rules;Studied the truss type steel reinforced concrete beam,steel concrete column under low reversed cyclic load node damage performance,combined with the new steel encased concrete node failure characteristics,established the truss type steel reinforced concrete beam,steel concrete column node,a seismic damage model is the model that node after the damage from the crack accumulation,sections and steel yield lose bearing capacity,reveals the damage process of nodes under earthquake load.The seismic damage model based on node analyses the section size,size and axial compression ratio on the framework of abdominal rod joints damage performance,the influence of damage under the action of the seismic load of new node failure process are analyzed.(4)Considering steel size was established by finite element method(fem),the size of the CHS,axial compression ratio and concrete strength of the design parameters,such as truss type steel reinforced concrete beam—section steel concrete column specimens of three—dimensional nonlinear finite element model,analyses the specimen under low reversed cyclic load of new steel encased concrete node of section steel,steel bar and concrete stress,such as load—displacement hysteretic curve and skeleton curve,and the shear bearing capacity of the node calculated,the theoretical research results with the test results are in good agreement,description of the node energy dissipation capacity and the seismic performance is higher.Column section study node size and helps to improve the bearing capacity of the new steel encased concrete node,diagonal size increases and the rational arrangement of abdominal rod can improve the shear capacity of nodes and energy dissipation capacity,the increase of axial compression ratio can slightly increase nodes carrying capacity,the increase of concrete strength capacity is larger,but the influence of axial compression ratio and concrete strength on the ductility is smaller.(5)Consistent with the node finite element analysis model,the separation method is adopted to establish the three dimensional space finite element model under quasi static load is analyzed,both cross as expected design reaches damage failure mode of the frame and the stiffness and bearing capacity in the degradation pattern of loading to destruction.Analysis of the truss type steel reinforced concrete beam,steel stress and damage mechanism of concrete column frame,frame load—displacement hysteresis curves,skeleton curves,etc.,it is concluded that increasing section size,the size of the abdominal rod can increase the ultimate bearing capacity,reasonable decorate diagonal size can improve the shear bearing capacity,ductility and energy dissipation capacity.(6)Through theoretical derivation,the truss type steel reinforced concrete beam—section steel concrete column nodes on shear bearing capacity analysis of each node is calculated from experimental data of the shear bearing capacity of core area and crack resistance bearing capacity calculation formula is deduced.Based on the shear mechanism of steel "frame—shear wall",the stress analysis was carried out on the core area of the node,and the formula of the shear bearing capacity of the joint was deduced and the influencing factors were analyzed.For new truss type steel reinforced concrete beam—section steel concrete column node design methods are presented,demand of component materials and structure of new steel flange of the steel encased concrete node generous than limit requirements are put forward.