| Structural vibration control has been widely used in structural engineering.As a kind of passive control,energy dissipation technology has developed rapidly.Energy dissipation technology is to reduce the vibration of the structure by installing energy dissipation devices in the structure.In this paper,a new type of energy dissipating damping member is researched,which is an energy dissipative support composed of a shape memory alloy(SMA)coil spring,and the influence of the parameters of the SMA spring energy dissipative support on the seismic performance of the frame structure is studied.First,the research parameters of the spring support as the energy dissipating member were determined,and the wire diameter ratio and pre-stretch length of the SMA spring were determined as the parameters of this article.Considering the parameters of the spring to be studied,combining the conditions of the laboratory and the test process,four sets of springs of different sizes were made.Four groups of springs were subjected to tensile tests under different working conditions.The forcedisplacement relationship of the springs was obtained based on the spring constitutive model,and a numerical model of the spring tensile process was established.The calculation results of the numerical model are compared with the data of the tensile test,and the correctness of the numerical model is verified.A dynamic model of a two-story steel frame with spring energy dissipating support was established.Numerical simulations were performed for multiple sets of seismic load conditions.The effect of SMA energy dissipative support on the seismic response of the frame structure was studied.Simultaneously,the values were simulated using shaking table tests.The calculation results are verified.The results show that the numerical simulation results agree well with the shaking table test results,which demonstrates the validity of the dynamic model established in this paper and lays the foundation for the next analysis.Based on the numerical model of a two-story steel frame with spring energy dissipative support,the influence of different spring parameters on the vibration reduction effect of the frame structure is analyzed.Simulation results and experimental results show that the optimal ratio of the diameter of the coil spring to the diameter of the wire can minimize the absolute acceleration and relative displacement of the frame structure.Meanwhile,if the pre-stretched length is set to an appropriate value,excellent vibration damping performance can be obtained.Compared with the frame structure without support,the frame with spring support shows satisfactory seismic performance under various seismic waves.Choosing an SMA spring with optimal parameters can achieve optimal vibration damping performance.It can be expected that the SMA spring support with better energy dissipation capacity and self-resetting performance has great potential in future energy dissipation applications of actual engineering structures. |
