Structural Dynamic Analysis of Wind Turbine Systems

1982 ◽  
Vol 104 (2) ◽  
pp. 89-95 ◽  
Author(s):  
R. W. Thresher
Keyword(s):  
Experimental Data ◽  
Dynamic Analysis ◽  
Natural Frequencies ◽  
Cyclic Loads ◽  
Current Analysis ◽  
Structural Dynamic ◽  
Horizontal Axis Wind Turbines ◽  
Analysis Computer ◽  
Computer Codes ◽  
Major Emphasis

The paper presents an overview of the dynamic analysis of horizontal axis wind turbines. The major emphasis of the paper is the review of current analysis methods and the comparison of results with experimental data. The current capabilities for predicting turbine system natural frequencies are discussed and the design implications of frequency placement are reviewed. The prediction of cyclic loads, using the dynamic analysis computer codes, is examined and comparisons are made between the code predictions and field test data. Finally, the dynamic analysis needs for advanced turbine systems are considered.

Dynamic Analysis of Structures with Interval Parameters under Stochastic Process Excitation

2014 ◽  
Vol 553 ◽  
pp. 699-704 ◽  
Author(s):  
Duy Minh Do ◽  
Wei Gao ◽  
Cheng Wei Yang ◽  
Chong Ming Song
Keyword(s):  
Stochastic Process ◽  
Particle Swarm Optimization ◽  
Dynamic Analysis ◽  
Optimization Algorithm ◽  
Natural Frequencies ◽  
Particle Swarm Optimization Algorithm ◽  
Particle Swarm ◽  
Mean Square ◽  
Structural Dynamic ◽  
Swarm Optimization

This paper presents the interval dynamic analysis of structures with uncertain-but-bounded parameters under stochastic process excitations. Structural natural frequencies and mean square values of structural random responses are not deterministic values but intervals. The interval problems are converted to optimization problems. Mathematical models are developed to find the bounds of interval natural frequencies and mean square displacements. An improved particle swarm optimization algorithm, namely lower sequence initialized high-order nonlinear particle swarm optimization algorithm, is employed to capture the exact bounds of structural dynamic characteristics and random vibration responses. Numerical example is used to demonstrate the presented method. Quasi-Monte Carlo simulations are also implemented to validate the change ranges of structural natural frequencies and mean square displacements produced by the proposed method.

scholarly journals Dynamic Analysis Technique of Rotating Centrifugal Impeller

1991 ◽  
Author(s):  
Jin Zhang ◽  
X. J. Chen ◽  
W. L. Wang
Keyword(s):  
Experimental Data ◽  
Dynamic Analysis ◽  
Natural Frequencies ◽  
Coupled System ◽  
Economic Benefits ◽  
Centrifugal Impeller ◽  
Stiffness Matrices ◽  
Analysis Technique ◽  
Reduced Coordinates ◽  
Made In

A dynamic analysis technique which can be employed in rotating centrifugal impeller is presented in this paper. It shows that multi–component partition can be made in repetitive sector region of the centrifugal impeller. The basic repectivie sector region of the centrifugal impeller is divided into three substructures: the full blade, the short blade and the sectorial part of the disc. By using Benfield mode substitution combined with group transformation successfully, the Hermite generalized mass and stiffness matrices under the reduced coordinates are derived. From this, the natural frequencies and the corresponding modal shapes of the bladed disc coupled system can be solved. The comparison of the analytical results obtained by using this method, other methods and the experimental data of models verifies the reliability, practicability and considerable economic benefits of the method presented in this paper.

A Study on the Natural Frequencies of Coupled In-Line Towers

1991 ◽  
Vol 113 (1) ◽  
pp. 81-85
Author(s):  
N. Qingde ◽  
C. Jiaqi ◽  
Z. Mingxian ◽  
H. Zenyan
Keyword(s):  
Experimental Data ◽  
Dynamic Analysis ◽  
Analytical Method ◽  
Natural Frequencies ◽  
Wind Loads ◽  
Seismic Loads ◽  
Wind Induced Vibration ◽  
Theoretical Results ◽  
Good Agreement

The natural frequencies of the coupled in-line towers are the most important parameters for dynamic analysis when the designer takes steps to assure that damages due to wind loads, seismic loads, or wind-induced vibration would not occur. In this paper the authors present an analytical method for determining these parameters. The theoretical results are compared with the experimental data obtained from the industrial towers in the field, and are in good agreement.

scholarly journals Structural Dynamic Analysis of the Chenderoh Dam Sector Gate Section

2018 ◽  
Vol 217 ◽  
pp. 02002 ◽  
Author(s):  
Mohamad Hazwan Mohd Ghazali ◽  
Mohd Hafiz Zawawi ◽  
Nurul Husna Hassan ◽  
Mohd Rashid Mohd Radzi ◽  
Ahmad Zhafran Ahmad Mazlan ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fe Model ◽  
Ansys Software ◽  
Structural Dynamic ◽  
The Real ◽  
Reference Information ◽  
Real Scale ◽  
Operational Methods

The dynamic characteristics such as natural frequencies, mode shapes and frequency response function (FRF) are the important characteristics to be investigated to access the level of durability of any dam structures. These characteristics are important since it will be the reference information for any operational methods to be used for the dam structures. In this study, one of the real dam (i.e., Chenderoh Dam) that available in Malaysia is taken into consideration, where the dynamic analysis of the sector gate section of the dam structure is investigated. the real scale of the sector gate section is measured on site and modelled into the CAD software with the consideration of real build-in materials. Then, the finite element (FE) model is constructed in ANSYS software with the required boundary condition and meshing sensitivity analysis. From the result of modal analysis, 30 natural frequencies are determined in the range of 0.5904 Hz to 8.471 Hz together with the mode shapes but only the most significant natural frequencies will be shown in this paper. In addition, all three axes of the FRF graphs show an agreement for the highest natural frequency value at 7.95 Hz, where the maximum deflection occurred in x axis direction with 2.03 × 10-7 m.

scholarly journals Spatially Resolved Experimental Modal Analysis on High-Speed Composite Rotors Using a Non-Contact, Non-Rotating Sensor

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Structural Dynamic ◽  
Spatially Resolved ◽  
Glass Fiber Reinforced ◽  
Vibration Responses ◽  
And Performance

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.

Numerical Simulation of a Jumper Conveying Slurry for Deep-Sea Mining

2021 ◽  
Author(s):  
Marcio Yamamoto ◽  
Tomo Fujiwara ◽  
Joji Yamamoto ◽  
Sotaro Masanobu
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Dynamic Analysis ◽  
Internal Pressure ◽  
Deep Sea ◽  
Petroleum Industry ◽  
Vertical Direction ◽  
Internal Flow ◽  
Horizontal Direction ◽  
Viscous Pressure

Abstract One key technology for Deep-Sea Mining is the riser system. The riser is already a field-proven technology in the Petroleum Industry. However, several differences exist between a petroleum production riser and a riser for Deep-Sea Mining, mainly related to the internal flow. The ore-slurry has a larger density than the hydrocarbons and shall be pumped with a much higher flowrate. The current software tools for riser’s dynamic analysis may include the internal fluid hydrostatic pressure and the centrifugal and Coriolis forces imposed by the bent pipe’s internal flow. However, the internal pressure drop is not calculated. The internal pressure alters the pipe’s effective tension and can alter the pipe’s bending moment changing its mechanical behavior. This article describes a computational script’s development to run embedded in a commercial software for riser’s dynamic analysis. Our script calculates the internal viscous pressure drop along with the jumper. This pressure is then converted into wall axial tension (buckling) and imposed on each node of the jumper’s numerical model. Each simulation case was calculated twice with and without the internal flow viscous pressure drop. The comparison with experimental data revealed that the jumper’s average position has a good agreement among all cases. However, the amplitude caused by the top oscillation showed some discrepancies. Experimental data has the highest amplitude in the horizontal direction, while the simulation without viscous pressure calculation had the smallest. The simulation with our embedded script had intermediary amplitude in the horizontal direction. The vertical direction amplitudes have the same behavior for all cases, but the experimental data showed the highest amplitude.

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