NEHRP Clearinghouse
- Title
- Random Response of Turbine Structures under Seismic Excitation.
- File
- PB87148748.pdf
- Author(s)
- Lin, Y. K.
- Source
- National Science Foundation, Washington, DC. Directorate for Engineering., November 1984, 177 p.
- Abstract
- The purpose of the study is to investigate the dynamic behavior of a wind turbine blade under seismic and turbulent wind excitations. Using the Markov process theory and Ito's stochastic differential equation, equations for statistical moments of blade response variables are derived. These equations then can be used to determine certain moment stability conditions for any given set of parameters, and moment responses if the system is stable. Results show that for a constant rpm wind turbine generator the uncoupled flapping, coupled flap-lagging, and coupled flap-lag-torsion of a wind turbine blade are very stable under normal operating conditions and that torsion has little influence on the dynamic behavior of flapping and leadlagging motions. If the system is stable, then the effect of turbulence on moment responses is greater than that of an earthquake; therefore, turbulence is likely the main cause for structural fatigue of wind turbine blades.
- Keywords
- Turbine blades; Wind turbines; Wind pressure; Turbulence; Earthquake engineering; Fatigue (Materials); Stochastic differential equations; Dynamic analysis; Markov processes