Development And Application Of Vibration Control System Based On Eddy-Current Damping And Inerter

Structural vibration control has always been one of the most important engineering difficulties in the field of civil engineering.At present,developing simpler and more efficient theory and technology of vibration control has always been the forefront of research in the field of structural vibration.One of the classical mature vibration control technologies is to install dampers.The introduction of Inerter(Inerter)with mass amplification effect in the field of mechanical engineering provides a new basic element for the development of dampers,and forms a two-dimensional "damping-inerter" vibration reduction system based on damping element and inerter element.In recent years,three-element tuned "damping-inerter" vibration reduction system coupled with spring elements has emerged rapidly on the basis of "damping-inerter" vibration reduction system,and the three-element vibration reduction system is expected to further improve the vibration effect of the structure.Based on the National Natural Science Foundation of China(NSFC)project " The theory and technology of three-element passive mitigation ofstructural vibration and its performance improvement for vibration control of stay cables "(51878274),one linear axial eddy-current damping-inerter systems(EVMD)and one non-linear axial eddy-current dampeing-inerter are developed to solve the problem of relatively little physical development and experimental verification of the current dampeing-inerter system prototype.On this basis,the conceptual design of TID and TVMD for tuned eddy-current damping-inerter system is studied by incorporating spring elements.The vibration reduction effects of VMD,TID and TVMD for stay cables are compared and analyzed by numerical simulation method.The main contents and conclusions of this paper are as follows:1)Theoretical and experimental study of linear or non-linear axial eddy-current damping-inerter system.One prototype of linear axial eddy current damping-inerter system(EVMD)and one non-linear eddy current damping-inerter system(NEVMD)were developed by integrating two nodal inertial elements based on ball screw and axial rotating eddy-current damping technology.The mechanical properties of the prototype were tested.Semi-theoretical semi-simulation of eddy-current damping force,three-dimensional finite element simulation of electromagnetic field and comparison of test results were carried out..The results show that both EVMD and NEVMD can achieve the dual efficiency of eddy-current damping and inertial quality,which significantly improves the energy dissipation efficiency of ECD.The semi-theoretical semi-simulation method based on the superposition calculation of axial rotating eddy-current damping monomer can guide the preliminary design of EVMD,and its finite element simulation method can basically meet the requirements of EVMD design accuracy;compared with EVMD,NEVMD shows good non-linear characteristics.2)Conceptual design of tuned eddy-current damping-inertia system.On the basis of EVMD and NEVMD,two kinds of three-element tune eddy-current damping-inerter systems,TID and TVMD,are designed.Then the overall structure and working principle of the two systems are clarified,and the prototype design of TID and TVMD is carried out.The results show that both TID and TVMD are feasible.The overall structure,working principle and design procedure of TID and TVMD can provide useful reference for the development of cable three-element prototype.3)Vibration control effect of VMD,TID and TVMD on stay cables is compared and analyzed.Based on complex modal analysis,the effects of inertance ratio,damping ratio and frequency ratio of vibration control system on additional modal damping ratio of tension-string cable are studied.The optimal parameters of VMD,TID and TVMD for vibration control of tension-string cable are obtained.The effects of VMD,TID and TVMD on vibration control of tension-string cable are compared and analyzed by numerical simulation.The results show that for the first modal vibration control of stay cables,the three-element vibration control system TID and TVMD are better than the two-element vibration control system VMD,and the three-element vibration control system TID is better than TVMD.With the increase of the inertance ratio of the vibration control system,the optimal control effects of VMD,TID and TVMD on the first modal vibration of stay cables are gradually improved.