| Steel structures have good mechanical performance and are increasingly widely used in industrial and civil construction fields.The progressive collapse of buildings caused by unexpected events such as explosions,collisions,and fires can also have adverse effects on society and huge economic losses,and steel structures are no exception.Selfcentering structures have the characteristic of reducing(or eliminating)residual deformation of structures,and have become a hot research topic in the field of seismic engineering in recent years.This article conducts a performance analysis on the resistance to progressive collapse of self-centering steel frame structures.The structural join of self-centering steel frame structure is seriously weakened due to the resetting requirements,and additional energy dissipation devices are needed to improve the energy dissipation mechanism of the structure,including two traditional typical energy dissipation mechanisms,namely yield energy dissipation and friction energy dissipation.This article selects two typical energy dissipation mechanisms of self-centering steel frame structures with yield energy dissipation components and friction energy dissipation components as the research object,and conducts research on the against progressive collapse performance of self-centering steel frames.The main research content and results are as follows:(1)Using ABAQUS finite element software,the correctness of the modeling of the self-centering node was verified through finite element analysis of the self-centering node with top and bottom angle steel and the self-centering node with web friction device.The accuracy of the against progressive collapse finite element modeling process was demonstrated through the analysis of a node like against progressive collapse finite element model.(2)Using ABAQUS finite element software,parameter analysis was conducted on the against progressive collapse performance of beam column nodes after removing the central column,clarifying the mechanism of each parameter on the against progressive collapse performance of self-centering steel frame structures,and exploring the against progressive collapse performance of self-centering steel frame structures.The results indicate that the initial prestress of the steel strand can affect the initial stiffness,plastic load,and maximum bearing capacity of the structure.With the increase of initial prestress,the plastic bearing capacity and maximum bearing capacity of the initial stiffness of the self-centering steel frame structure with top and bottom angle steel and the self-centering steel frame structure with web friction device are both improved.(3)The magnitude of the bolt pre tightening force can affect the initial stiffness of the structure and the bearing capacity values at each stage.As the bolt pre tightening force value increases,the initial stiffness and bearing capacity of the self-centering steel frame with web friction device and the self-centering steel frame with top and bottom angle steel all increase.The friction coefficient between the friction plate and the web can affect the plastic bearing capacity and initial stiffness of the structure.Increasing the friction coefficient will increase the plastic bearing capacity and initial stiffness of the structure,but it has almost no effect on the bearing capacity of the catenary stage of the structure.(4)Based on the principle of component modeling,the two types of connections between the self-centering steel frame with top and bottom angle steel and the selfcentering steel frame with web friction device are decomposed into several basic components that contribute to the stress,and these basic components are integrated to simulate the mechanical performance of the entire node,and corresponding numerical analysis models are established accordingly.By comparing the results with the refined model,it is shown that the node component model can accurately reflect the stress development process and fracture path of the node,while reducing computational costs.And using the component method to simplify the calculation model and compare the against progressive collapse performance of two other models with the same parameters,connecting them to obtain the differences in the against progressive collapse performance of the two energy dissipation mechanisms of self-centering steel frame. |
