Research On Hysteretic Behavior Of Sliding Self-Centering Steel Brace

In recent years,through continuous in-depth research by scholars at home and abroad,the structural form,reset materials,and design concepts of self-centeringting steel braces have been in constant development and improvement.At present,there are still some disadvantages of the reset material used in self-centeringting steel braces: when using prestressed steel strands as the reset material,it is necessary to ensure that it is always in an elastic state to ensure the reset effect,resulting in limited support deformation capacity and under normal use,The natural relaxation of prestress will greatly weaken the reset effect of the support;when shape memory alloy(SMA)is used as the reset component,due to the full hysteresis curve of the energy dissipation system,the amount of SMA is too large,the cost is high,and SMA is more affected by temperature Large,the performance is not clear in extreme cases such as fire;when the composite fiber reinforcement is set as a reset component,there are problems such as easy slippage of the anchor end,immature processing technology,and performance indicators that cannot meet the requirements for use.Based on this,this subject proposes a sliding self-centering steel brace(S-SCB for short)that uses a disc spring as the reset component and a steel rod with pinch-retraction hysteresis as the energy-consuming component).Carried out experimental research and numerical simulation analysis,studied the influence of various parameters of S-SCB steel brace on its bearing capacity,stiffness,ductility,reset effect,etc.,and applied S-SCB steel brace to the frame structure,studied S-SCB steel brace affects the performance of the frame.The main research work is as follows:(1)The basic structure of the S-SCB steel brace test piece is proposed,the working principle of the steel brace is briefly described,and the pure energy-consuming steel brace(S-SB),pure reset steel brace(S-SC)and self-Three 1/3 scale test specimens of reset sliding steel brace(S-SCB)were used to carry out low-cycle reciprocating loading tests,and the effects of reset system and energy dissipation system on the bearing capacity,reset capacity and energy dissipation capacity of the support were investigated respectively.The mechanical properties such as hysteretic performance,axial stiffness,bearing capacity,energy dissipation capacity and resetting capacity of S-SCB steel brace were evaluated.(2)The ABAQUS finite element software was used to establish the refined finite element models of the test specimens S-SB,S-SC,and S-SCB respectively.By comparing with the test results,the rationality and accuracy of the numerical simulation were verified.Subsequent parametric finite element analysis provides the basis.(3)The ABAQUS finite element software is used to perform parameter finite element analysis on the S-SCB support,focusing on the main design parameters such as the preload,stiffness,energy dissipation steel bar section size of the reset system,and the combination of two group disc springs in parallel.Influence of hysteresis curve,skeleton curve,lateral stiffness,ductility and hysteretic energy consumption.(4)The Open Sees software was used to establish a macro finite element model of the steel frame structure with ordinary BRB support and S-SCB steel brace respectively.The cyclic Pushover analysis of the structure under two different load distribution modes was carried out.Performance under different load distribution modes.