Research On Seismic Performance Of Concrete Frame Structures

Researchers generally assume concrete frame joints as rigid in conventional structural design and analysis.However,a large number of earthquake disaster investigation results indicate that the failure of the joints of the frame structure may lead to the local destruction of the structure or the overall collapse.Therefore,starting from the joint models to study the seismic performance of concrete frame structures has engineering and theoretical significance.On the basis of studying the mechanical characteristics of concrete frame joints,The author utilize the BeamColumnJoint element and bond-slip element of the finite element platform OpenSEES,establishing the concrete frame Pseudo-static and Pseudo-dynamic finite calculation models which considering beam-column joint models.analysing Seismic performance tests of concrete frame structures which tested by domestic researchers.Besides,the author make some parametric analysis of the seismic performance of concrete frame structures based on beam-column joint models,joint stirrup ratio,axial compression ratio,structure height.Proposing some suggestions for seismic design of concrete frame structures based on the calculation results,The main research contents are as follow:(1)Through extensive readings of domestic and foreign literature.Introducing the research situation of the joint finite element model of concrete frames in detail.Summarizes the status quo of domestic and international research on the concrete frame joints and integral concrete frame structures which considering joint models.Putting forward some problems in the analysis of seismic performance of existing concrete frame structures and in the necessity of further research on concrete frames.(2)Elaborating the mechanism of the joints of concrete frame structure,introduced BeamColumnJoint element in OpenSEES.establishing the concrete frame Pseudo-static calculation models,analysing two Two-Bay Two-Storey concrete frames under low cycle loading which tested by domestic researchers.The calculated results agree well with experiment results.providing a new way for seismic analysis of concrete frames under Low-cycle repeated load.(3)Establishing the concrete frame Pseudo-dynamic finite calculation models which considering beam-column joint models.Analysing some Pseudo-dynamic test of concrete frame structures which tested by domestic researchers.The calculated results agree well with experiment results.Proving the applicability of BeamColumnJoint element and bond-slip element of OpenSEES in seismic performance analyse of concrete frames and accuracy of finite calculation models which considering beam-column joint models in analysis of Pseudo-dynamic tests.(4)The author designed some concrete frames based on beam-column joint models,structure height.establishing the concrete frame finite calculation model which considering beam-column joint models based on OpenSEES,analysing concrete frame structures under earthquake loads.The analytic results indicate that rigid assumptions on frame joints would underestimate the amount of lateral movement of the structure.The effects of the deformation of the joint area on the seismic performance of the frame structure will decrease with the increase of the building height.Besides,the author makes some parametric analysis of concrete frames based on joint stirrup ratio and axial compression ratio.Proposing some suggestions for seismic design of concrete frame structures.