Study On Seismic Performance Of End-reinforced Steel Pipe Damper

To address the problem of premature end damage of steel pipe dampers which affects the working performance of the damper,a new type of steel pipe damper called End-reinforced Steel Pipe Damper(ESPD)is proposed,and its structure,working principle,and characteristics are described.Through mechanical property tests,finite element analysis,and structural analysis,the mechanical properties,effects of structural parameters,and practical engineering applications of ESPD are studied.The main research contents and conclusions are as followed:(1)Finite element simulation analysis of the proposed end-strengthened steel pipe damper using ABAQUS finite element software was conducted to verify the feasibility of the endstrengthened structure.The results show that the end-strengthening structure can better improve the energy dissipation performance of the steel pipe damper and alleviate the premature withdrawal of the damper due to the end damage of the steel pipe damper.(2)One steel pipe damper and three end-strengthened steel pipe dampers were fabricated,and the key performance parameters of the end-strengthened steel pipe dampers were studied through low circumferential reciprocal loading tests.The test results show that: the hysteresis curve of the end-strengthened steel pipe damper is symmetrical and full,with good energy dissipation performance;the end-strengthening structure of the reinforced steel pipe can effectively delay the cracking of the end of the steel pipe to avoid the loss of load-bearing capacity and withdrawal of the damper due to premature cracking,so as to give full play to the energy dissipation capacity of the damper.(3)ABAQUS finite element software was used to study 15 end-strengthened steel pipe dampers with different construction parameters,and to study the influence of key construction parameters such as height-to-diameter ratio on the mechanical properties of end-strengthened steel pipe dampers,and to give the corresponding recommended values.It is suggested that the height-to-diameter ratio should be 1.5 ～ 2.5;the thickness-to-diameter ratio should not be greater than 6%;the reinforcement thickness ratio should be 1.67 ～ 2;and the reinforcement length ratio should not be less than 0.47;(4)The actual damping performance of the end-strengthened steel pipe dampers was studied through the time course analysis of the damping structure equipped with endstrengthened steel pipe dampers under the effect of multiple and rare earthquakes by ETABS and SAUSAGE software respectively.The study showed that the seismic response of the endstrengthened steel pipe dampers was significantly improved compared with the original structure under multiple and rare earthquakes.