Amirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X52320200521Horizontal and Vertical Vibration Control of The Power Transmission Tower Cable
Using Optimal TMDsHorizontal and Vertical Vibration Control of The Power Transmission Tower Cable
Using Optimal TMDs769780322410.22060/ceej.2019.14862.5765FAAkbarBathaeiEarthquake Engineering Department, University of Tehran, Tehran, IranMeysamRamezaniinternational institute of earthquake engineering and seismologyS. MehdiZahraiSchool Civil Engineering, University of Tehran, Tehran, Iran0000-0003-2759-2424Journal Article20180820Using Tuned Mass Dampers (TMDs) is among the most typical methods for passive control of structures subjected to earthquake excitations. TMDs often reduce the displacement response of structures by influencing their first mode of vibration. The structure of these dampers consists of three main parameters: mass, damping, and stiffness. Since the parameters of TMDs are constant during the vibrations, optimal tuning of these parameters is very important. Finding the optimal values of the key parameters for a TMD in nonlinear structures using numerical methods involves numerous nonlinear dynamic analyses; therefore, the computations would be time-consuming. Recent studies, carried out on the application of the TMDs in the building structures, have mainly focused on reducing the lateral displacements of the building structures. However, in this research, the application of TMDs and their effectiveness were investigated for cables of the power transmission tower in both the lateral and vertical directions simultaneously. In order to numerically study the behavior of the power transmission tower, the structure of the telescopic steel tower was modeled in the OpenSEES software and to reduce the volume of computation, a numerical search method was used to find the optimal values for the parameters of the TMDs to minimize the lateral displacement in the middle of the cable span. The mass ratio of the TMDs was equal to 0.5% of the total mass of the structure. Using this mass ratio, numerical analyses of the system indicated that the maximum reduction of the lateral displacement in the middle of the cable mitigated due to implementing the TMDs is about 50% under the applied earthquakes with 0.5g maximum acceleration.Using Tuned Mass Dampers (TMDs) is among the most typical methods for passive control of structures subjected to earthquake excitations. TMDs often reduce the displacement response of structures by influencing their first mode of vibration. The structure of these dampers consists of three main parameters: mass, damping, and stiffness. Since the parameters of TMDs are constant during the vibrations, optimal tuning of these parameters is very important. Finding the optimal values of the key parameters for a TMD in nonlinear structures using numerical methods involves numerous nonlinear dynamic analyses; therefore, the computations would be time-consuming. Recent studies, carried out on the application of the TMDs in the building structures, have mainly focused on reducing the lateral displacements of the building structures. However, in this research, the application of TMDs and their effectiveness were investigated for cables of the power transmission tower in both the lateral and vertical directions simultaneously. In order to numerically study the behavior of the power transmission tower, the structure of the telescopic steel tower was modeled in the OpenSEES software and to reduce the volume of computation, a numerical search method was used to find the optimal values for the parameters of the TMDs to minimize the lateral displacement in the middle of the cable span. The mass ratio of the TMDs was equal to 0.5% of the total mass of the structure. Using this mass ratio, numerical analyses of the system indicated that the maximum reduction of the lateral displacement in the middle of the cable mitigated due to implementing the TMDs is about 50% under the applied earthquakes with 0.5g maximum acceleration.https://ceej.aut.ac.ir/article_3224_fc845a2827daf02d8dafef6fbaf8b17e.pdf