Traditional buckling restrained brace(BRB)only provides stiffness but not damping for structures under minor earthquakes,and is prone to produce large residual deformation under major earthquakes.In order to make up for the above defects of BRB,a new double-level yielding self-centering buckling restrained brace(DY-SCBRB)was proposed in this paper.In minor earthquakes,the brace yields to dissipate energy in advance and provides additional damping for the structure.In major earthquakes,the brace further dissipates energy and provides the structure with resetting ability.Through the structural analysis of DY-SCBRB,the working principle of the brace was obtained and the load-displacement hysteretic relationship restoring force model of the brace was established.The double-level energy dissipation characteristic and self-centering capability of the brace were effectively verified.The static loading of DY-SCBRB was carried out by ABAQUS software to analyze and verify the hysteretic performance of the new brace,and the influence rule of the first stiffness ratio β1,the second stiffness ratio β2,the reset ratio αc and the yield displacement ratio αyc of the brace on the hysteretic performance of DY-SCBRB was found,and suggestions on the value of the brace performance parameters were given.The results show that DY-SCBRB not only has significant double-level energy dissipation characteristic,which can realize the whole stage of energy dissipation under different levels of earthquakes,but also has strong self-centering ability,which can greatly reduce the residual deformation of structures after earthquake.The ultimate bearing capacity can be improved with the increase of the β1 and β2.The smaller β1 and β2 are,the stronger the energy dissipation capacity will be.The changes of β1 and β2 have no effect on the initial stiffness and resetting capacity of the brace.The values of β1 and β2 are recommended to be 0.78-1.58 and 0.006-0.014,respectively.The increase of αc can improve the initial stiffness and resetting ability of the brace,while the decrease of αc is conducive to enhancing the energy dissipation capacity of the brace under minor earthquakes.αc is recommended to be 0.75-1.25.The smaller the αyc,the better the comprehensive seismic performance of the brace.The recommended value of αyc is 0.5-1.5.
self-centering buckling restrained bracedouble-level yieldingrestoring force modelhysteretic performanceparameter analysis
万方数据
维普
