Finite Element Model Of Tower Research Articles

Seismic Vibration Mitigation of Wind Turbine Tower Using Bi-Directional Tuned Mass Dampers

Wind turbines have been increasingly erected in earthquake regions to harvest abundant wind energy. However, the wind turbine tower is slender and lightly damping, which exhibits high susceptibility to earthquake-induced vibration. It is challenging to mitigate the seismic vibration of the tower. In this study, a bi-directional tuned mass damper (BTMD) is proposed to mitigate the seismic vibration of the wind turbine tower. Meanwhile, a lumped-mass finite element model (LFEM) and a coupled blade tower finite element model (CBFEM) are used to investigate the vibration mitigation performance of the BTMD. First, the BTMD and corresponding dynamic equilibrium equations are systemically introduced. Accordingly, the optimum stiffness and damping of the BTMD at different mass ratios are investigated. Then, the dynamic prosperities of the LFEM and CBFEM are compared. Subsequently, the seismic responses of the wind turbine with the BTMD are conducted using the LFEM and CBFEM. Meanwhile, the mitigation performances of the BTMD under uni- and bi-directional earthquakes are investigated. The displacement, acceleration, and bending moment of the wind turbine tower are analyzed in time domain and frequency domain. Note that the influential factors, including mass ratio and structural frequency, on the vibration mitigation performance of the BTMD are investigated. Results show that the proposed BTMD can significantly mitigate the peak values of the top displacement and bottom bending moment. However, the blade tower coupling effect and frequency variation of the tower would have influences on the mitigation efficiency of the BTMD. The results enable a better understanding of the seismic vibration mitigation of the wind turbine tower using tuned mass dampers.

Research on Condition Assessment Method of Transmission Tower Under the Action of Strong Wind

Transmission towers are often subjected to the external damage of severe weather like strong wind and so on, which may cause the collapse due to the yield and fracture of the tower material. Aiming this issue, an assessment method was proposed in this paper to assess the operation condition of transmission towers under strong wind. With a reasonable assess index system established firstly, then the internal force of the tower material was solved and its stability was determined through the mechanical analysis of the transmission tower finite element model. Meanwhile, the condition risk level of the tower was finally determined by considering the difference among the influences of other factors like corrosion and loose of members, slope on the transmission tower through the analytic hierarchy process. The assessment method was applied to assess the wind-induced collapse of towers in 110kV Bao Yi II line in Wenchang City, Hainan Province, of which the result proves the method can assess the condition of transmission tower under strong wind and of guiding significance for improving the windproof capability of transmission towers.

Study of Intake Tower under an Earthquake Using the Power Spectral Method Based on ANSYS

In this paper, the power spectral density method based on ANSYS is carried out to study the intake tower finite element model under an earthquake. A power spectral density function is obtained and disposed to be smooth. Then it is used to study the intake tower when the seismic wave occurs in the direction of flow and perpendicular to the direction of flow .This study provides theoretical basis for reinforce and transform of the intake tower structure.

Parametric Modeling of Whole Tower Crane Based on ANSYS

The conventional finite element modeling of the tower in the ANSYS GUI, in particular, the modeling of the whole tower crane which is large and complex, always gives rise to low efficiency and less authenticity. A new method of modeling of whole tower crane is presented here. This paper applies the APDL which stands for ANSYS Parametric Design Language to separately build crane’s components :the mast, the tower head, the counter-jib ,the jib and the simplified slewing platform. And then accomplishes the parametric finite element model of the whole tower by using the assembly and connection technology provided by ANSYS to assemble and connect them. Further, based on these methods and Visual Basic Programming Software, the parametric design software on tower crane has been developed. At the end of the paper, the paper takes the H25/23 tower crane as an analysis example to demonstrate that such a method is not only technically feasible, but also cost-effective. The details of the parameterized modeling and related technologies are given in the paper.

Seismic Performance Analysis of a Hollow Tower Structure with Three Prismatic Section

In order to better understand seismic performance of tower body structure in a square, the symbol tower finite element model is established using the finite element software ANSYS. Modal analysis is carried out and the first 3 natural frequencies and vibration modes of marking tower are obtained. By selecting 2 group natural seismic waves and a synthetic seismic wave the seismic time-history analysis of the model is performed, the symbol tower response under the earthquake action is obtained and the maximum lateral displacement and the maximum stress of symbol tower meet the standard requirements, so mark tower under earthquake are safe. These can provide reference for the same type of engineering design.

Rain-Wind-Induced Vibration Control for Long Span Transmission Tower

In this paper, multiple tuned liquid dampers control for rain-wind-induced response of long span transmission tower is investigated. Equations of motion for a structure-TLD system are derived. According to the mechanism of vibration control, rain-wind-induced vibration control for tower model with multiple tuned liquid dampers is carried out by using numerical simulation. Three-dimensional finite element model of tower based on a real project is established. Rain-wind load time history is simulated based on wind and rain theory. Time history curves and the maximum responses without and with tuned liquid damper under rain-wind excitation are analyzed and discussed. The results show that the tuned liquid damper could decrease the rain-wind-induced response of long span transmission tower, and the device could be installed in tower when the response too large.