Doctoral Dissertations

Keywords and Phrases

Aerodynamic and Seismic Load Interaction; Buckling and Fragility Analysis; Finite Element Method and Nonlinear Dynamic Analysis; Structural Dynamics and Seismic Response

Abstract

"With the advancements in the wind energy production industry, the demand for a cost effective and safe design of wind turbine structures is growing rapidly. The wide deployment of wind turbines in locations with high seismic hazard has lead engineers to take into account a more comprehensive seismic design of such structures. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module has been developed for the publicly available National Renewable Energy Laboratory (NREL) code, FAST, at the first step of this research. This achievement allows engineers working in this industry to directly consider interaction between seismic and other environmental loads for turbines with a freely available simulation tool. The first paper details the practical application and theory of these enhancements and provides examples for the use of different capabilities. The platform is then used to show the suitable earthquake and operational load combination with the implicit consideration of aerodynamic damping by estimating appropriate load factors.

In the next step, the developed platform is used to evaluate the effects of aerodynamic and seismic load coupling on the power generation and structural dynamics behavior of wind turbines. Various turbine operation scenarios such as (i) normal operational condition, (ii) idling, and (iii) earthquake induced emergency shutdown are simulated to show the differences in generated power and dynamic response of wind turbine structures. The effects of aerodynamic damping and pitch control system are presented which show reduction in the resulting design demand loads.

In the last step, a finite element model of the turbine which is calibrated with the previously implemented code is used to evaluate the fragility of wind turbines under seismic and wind excitation. This is obtained by the assessment of nonlinear dynamic behavior of a 5-MW NREL wind turbine considering different earthquake and wind intensities using the finite element model. Engineering Demand Parameters (EDP) and Intensity Measures (IM) are then obtained from Incremental Dynamic Analysis (IDA) and used to assess the probability of exceeding different Damage States (DS) using fragility curves."--Abstract, page iv.

Advisor(s)

Schonberg, William P.

Committee Member(s)

Volz, Jeffery S.
Chen, Genda
ElGawady, Mohamed
Chandrashekhara, K.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2015

Journal article titles appearing in thesis/dissertation

  • A computational platform for considering the effects of aerodynamic and seismic load interaction for multi-megawatt utility scale horizontal axis wind turbines
  • Effects of seismic and aerodynamic load interaction on the power generation and structural response of multi-megawatt utility scale horizontal axis wind turbines
  • Fragility analysis of a 5-MW NREL wind turbine considering aero-elastic and seismic interaction using finite element method

Pagination

xii, 150 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2015 Mohammad-Amin Asareh, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Wind turbines
Wind turbines -- Earthquake effects
Renewable energy sources
Earthquake engineering

Thesis Number

T 10706

Electronic OCLC #

913413867

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