Study On Hysteretic Performance Of Displacement Amplification Self-Centering Energy Dissipation Braces

The traditional Self-centering Energy dissipation Braces(SCED)usually enhanced deformation and energy dissipation ability by using Shape Memory Alloy(SMA)、Carbon Fiber Reinforced Plastic(CFRP)and other materials as self-centering system.However,using SMA and CFRP to form the self-centering of SCED would increase the cost of SCED.Besides,SCED usually applied prestress to tendons during the assembly stage,which reduced the deformation ability of braces.In order to solve the questions above,the paper had done some work as follow.1.Aim at the questions of limited deformation ability and high cost of traditional SCED,two novel SCED with good deformation,self-centering and energy dissipation capacity and low cost were proposed in this paper.The structure,working mechanism and restoring force model of braces had been introduced in detail,and the key parameters affecting the performance of braces were determined.2.Based on the restoring force model,the key parameters affecting the hysteretic behavior of NSC-BRB were determined,and 20 finite element models of NSC-BRB were established by ABAQUS software for analysis.The results shown that the NSC-BRB could change the working stage of self-centering system by the relationship between axial force of brace and slip force of friction device,which could avoid the fracture of tendons and enhance the deformation ability of brace.The energy dissipation ability of brace could enhance by reducing the slip force of friction device,but the residual displacement of brace was big after loading.Finally,the optimization design method had been proposed by comparing the NSC-BRB simulation results with the restoring force model analysis results.3.Based on the restoring force model,the key parameters affecting the hysteretic behavior of NSCB were determined,and 22 NSCB numerical models were established for analysis.The results shown that the NSCB could have good self-centering ability by changing the stiffness of self-centering system during loading.The measure could avoid reducing the deformation of self-centering system and enhance the deformation ability of brace.After the simulation was completed,the mechanical properties of each brace had been summarized.Then,the simulation results were compared with the analysis results of the restoring force model,and the optimization design method had been proposed.4.In order to verify the proposed NSCB,the Pseudo-static test of NSCB subsystem was completed in the last chapter.The material property test,component design and manufacture,installation and debugging and data processing of NSCB test was introduced in detail,and the test results of NSCB was compared with the simulation results.The results shown that NSCB could have good displacement and self-centering ability in the loading process.Under the premise of exerting only 50% deformation capacity of the self-centering system,the maximum axial deformation of the NSCB could reach 20 mm,and the residual deformation was 1.8mm.