Research On The Damping Performance Of SMA Rod-type Damper On Stay Cables

Shape memory alloy(SMA)possesses higher elasticity than general materials,a specific shape memory effect,high damping capacity,strong corrosion resistance,and great fatigue resistance,as well as self-perception and self-adaptation features.It is a great material for structural vibration control and has a wide range of applications.This article focuses on mechanical performance testing on super-elastic SMA rods due to the special properties of shape memory alloys.It is recommended that super-elastic SMA rods be used to replace the steel strands in present dampers that are prone to strand breakage,and that this minimizes vibration and energy consumption of stay cables.The following are the key findings of the study:(1)The research progress and general status of stay cable vibration reduction,SMA,and damper at home and abroad are evaluated,as well as the thesis' research content and importance.(2)The stress-strain relationship,energy dissipation capacity,equivalent damping ratio,and other aspects such as cycle periods,pre-tensioning or not,different diameters,different loading rates,and different strain amplitudes are explored through mechanical performance testing of super-elastic SMA rods.The residual strain and other associated mechanical property parameters are influenced,and the relationship between the mechanical property change function and the relationship between the mechanical property change function is simply fitted.(3)The mathematical model is established,and the correctness of the theoretical model is validated through the comparison of the finite element model.Super-elastic SMA rods are utilized to replace the steel strands in the common domestic FD and FR dampers.Then,using the SMA-FD type damper as an example,investigate the effects of various structural parameters on the frequency characteristics of the damper;measure the natural frequencies of the FD and FR types dampers using SMA bars of various diameters.The results are compared to their theoretical values and assessed.(4)Study the vibration control effect of the damper on the stayed cable,establish the motion equation and state equation of the cable damper system,use the complex eigenvalue method to analyze the modal damping ratio of the coupled system,and take its modal damping ratio as the optimization objective,Using the controlled variable method to optimize and analyze its various modal parameters to provide the optimal parameters for subsequent research.