Research On The Method Of Structural Vibration Control Based On Shape Memory Alloy Self-centering Energy Dissipation Brace

It has been proved that the energy dissipation technology can considerably improve the performance of the structure under the earthquake and strong wind.In recent years,some passive energy dissipation devices with strong energy dissipation capability,self-centering capability,and simple structure have also been researched by many scholars.As a relatively new intelligent material,shape memory alloy(SMA)has the characteristics of large recoverable deformation,high damping,good fatigue resistance,etc.SMAs have gained increasing attention in the field of structural vibration control.Based on SMA's unique performance many researches have been done to offer new self-centering devices.In this study,a new self-centering energy dissipation brace using SMA as the core element is designed based on the tensile test of SMA elements with different forms,the seismic performance of the brace was also studied through numerical simulation.This study consists of 4 main parts:(1)The basic characteristics of shape memory alloy are briefly introduced,and the problems of SMA in practical application are summarized.The mechanical properties of superelastic SMA wires and cables were tested.The effects of cycle times and strain amplitude on the mechanical properties of SMA elements were analyzed and compared.The mechanical properties of SMA wire and cables were simulated by using Abaqus finite element software.(2)Based on the performance of the SMA elements,a new self-centering energy dissipation brace was designed and developed.Two sets of SMA cables were used in the device.Thus,the brace can use the maximum superelastic capacity of the SMA cables regardless of compression or tension.(3)Abaqus finite element software was utilized to simulate the mechanical properties of the self-centering energy dissipation brace,the influence of factors on the performance of brace has also been studied and analyzed,such as the number of cables and the degree of pretension.(4)Non-linear dynamic time-history analysis and Pushover analysis were conducted to study the effects of the new SMA self-centering energy dissipation brace on the seismic response of a nine-story frame structure.The analyses show that the new SMA self-centering energy dissipation brace has an obvious effect on the vibration control of the structures,it can improve the self-centering ability of the structure significantly,and it also reduces the residual deformation of the structure.