Research On Seismic Performance And Progressive Collapse Resistance Of Steel Frame Structure With Replaceable Energy Dissipating Beam

As a form of recoverable functional structure,a structure with replaceable energy dissipating beam section has the advantages of being able to recover after earthquake and controlling the damage location.The recoverable functional structures have been developed rapidly in recent years.At present,most of the existing researches on replaceable energy-dissipating beam section structures focused on the seismic performance of the joints,and there were few studies on the seismic performance,replaceability of beam section and the progressive collapse resistance of steel frame structure with the replaceable energy-dissipating beam sections.Aiming at the existing problems at the present stage,the author designed the flange-weakened and web-opened beam-column joints with replaceable energy-consuming beam sections.On one hand,the low yield point steel was used to make the replaceable beam section of the new joint to realize concentrated damage and energy consumption;On the other hand,the replaceable beam section and the steel beam were bolted by the end plate to reduce the welds on the site as far as possible and facilitate the assembly construction.The ABAQUS finite element software was employed to carry out the pseudo-static analysis of the flange-weakened and web-open beam-column joints with replaceable energy-consuming beam sections and single-layer single-span plane frames with flange-weakened single-span frames.Then,the dynamic elastic-plasticity time-history analysis and progressive collapse resistance research of multi-scale model of steel frame with the flange-weakened replaceable energy dissipating beam section and the ordinary rigid-jointed steel frame were carried out respectively.The specific research contents are as follows:(1)This paper introduces the types and development process of recoverable functional structures,summarizes the research situation in this field at home and abroad,focuses on the research progress of the structure with replaceable energy dissipation components,and reviews the existing problems.(2)The operation method and parameter setting used in the modeling process of ABAQUS finite element software are described in detail,including material constitutive,element type selection,mesh division,etc.,and the settings of contact and constraint relationships between different components are emphatically introduced.(3)The flange-weakened and web-opened beam-column joints with replaceable energy-consuming beam sections are designed,and the numerical models of these joints are established for quasi-static analysis.The hysteretic behavior,stiffness,bearing capacity,ductility and energy dissipation index of the joints are studied,and the deformation and failure characteristics are analyzed.The quasi-static analysis of the flange-weakened single-layer single-span plane frame is carried out to study its hysteresis performance and deformation,and the parameters such as endplate opening gap and endplate corner deformation are analyzed to provide a basis for the simplification of the overall plane frame.(4)The multi-scale models of steel frame structure with flange-weakened replaceable energy-dissipation beam section and ordinary rigid frame structure with weakened flange are established separately.The elastic-plastic time history analyses are conducted to study their seismic responses of the top displacements,base shears and interlayer displacement angles of the structures,and analyze whether they can meet the seismic performance requirements.Parameters such as structural damage,residual deformation and rotating angle of the end-plate are also studied to analyze whether the structure can be replaced after seismic damage.(5)The nonlinear dynamic collapse analyses of the steel frame structure with flange-weakened replaceable energy dissipation beam section and the ordinary rigid-joint steel frame structure are carried out seaprately.By studying the vertical displacements of the failure point and the deformations of the component,the progressive collapse resistances of the two kinds of steel frame are compared,and the influence of replaceable energy dissipation beam section on the progressive collapse resistance of the structure is discussed.