Experimental Research Of All-Steel Buckling Controllable Brace

Earthquakes and natural disasters have occurred frequently in recent years,which threaten the safety of human life and property.Countries all over the world have paid more and more attention to the research on engineering earthquake resistance,and China has the anti-seismic requirements as mandatory standards by formulating relevant regulations.As a commonly used seismic component,braces are widely used in various fields of engineering.Conventional braces are extremely prone to global or local buckling instability and damage under conditions of fortification intensity and large earthquakes.In order to solve the buckling instability of supports under rare earthquakes,buckling restrained brace are usually used in actual engineering.Because the buckling restrained brace adopts the structural form of the core force member and the outer restraint member,the support can achieve the ideal state of full-section yielding without buckling when the force is applied,forming a full hysteresis curve,providing better bearing capacity and superiority energy consumption.This paper proposes a new type of buckling restrained brace: the all-steel buckling controllable brace core is a force-bearing component consisting of a circular tube and a loading end connected by welding.The loading end consists of four right-angled trapezoid gussets and an isosceles trapezoid The loading plate is composed;the outer restraint member is welded by two channel steels and two T-shaped steels,and the length of the T-shaped steel web is adjusted by cutting.The buckling controllable brace has no adhesive material between the inner and outer pipes,so it has the characteristics of light weight and easy fabrication and assembly.The biggest advantage is that it can form a buckling controllable brace for the existing traditional single-pipe support and external restraint members.This article first introduces the working principle,composition and theoretical formula of the brace.The theoretical research includes the overall stability,local stability of the buckling-controllable support,and the value of the gap between the core force member and the external restraint member.The theoretical formulas of the maximum critical stress,the limit value of width-to-thickness ratio,and the minimum gap value were given.Secondly,this paper conducts experimental research on the model.The core stress members and external restraint members are made of ordinary Q235 b steel,and subjected to axial cyclic reciprocating loading according to the loading system designed inaccordance with China's seismic code.When the end is fixed at one end and hinged at the other end,the two brace loading ends are offset Form of shaft failure;when the two ends are fixed,the buckling controllable brace is caused by the multi-wave buckling of the inner tube,and the traditional brace is caused by instability.At the same time,after collecting and sorting out the experimental data,the seismic performance indicators such as tension and compression symmetry,skeleton curve,stiffness degradation,energy dissipation capacity,stress and strain were analyzed.Experiments show that: under the boundary form of one end fixed and one end hinged,the buckling controllable brace is 56% higher than the traditional brace;under the boundary condition fixed at both ends,the energy consumption capacity is increased by 63%,so The energy dissipation capacity is better than the boundary form fixed at one end and hinged at the other end,and it fully demonstrates that the buckling controllable brace has a significantly improved energy dissipation capacity compared to traditional braces.Finally,on the Abaqus finite element software platform,a full-scale model of the traditional brace and buckling controllable brace under the boundary conditions of consolidation at both ends was established according to the support size,and the relevant parameters of the mechanical model were calculated.The finite element software simulation results are compared with the experimental results to compare energy consumption performance and bearing capacity.Through comparison,it is found that although there are certain errors in the finite element simulation,the bearing capacity and energy consumption performance of the component can still be reflected on the whole,so it is feasible to use the finite element simulation engineering example.Figure [50] table [11] reference [61]...