Vibration characteristics of a large wind turbine tower on non-rigid foundations /  
Suey T. Yee...[et al.] 
 - Cleveland :   National Aeronautics and Space Administration,   1977 Washington :   Energy Research and Development Administration  1977 
 - 23 p. :   figuras 
 - ERDA/NASA .
<br/><br/> Informe/número de patente ERDA/NASA-1004/77/1  NASA TM X-73670 
<br/><br/>Vibration characteristics of the Mod-OA wind turbine supported by nonrigid foundations were investigated for a range of soil rigidities. The study shows that the influence of foundation rotation on the fundamental frequency of the wind turbine is quite significant for cohesive soils or loose sand. The reduction in natural frequency can be greater than 20 percent. However, for a foundation resting on well graded, dense granular materials or bedrock, such effect is small and the foundation can be treated as a fixed base. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>ENERGIA EOLICA<br/>TURBINAS EOLICAS<br/>PRODUCCION DE ENERGIA<br/>CONVERSION DE ENERGIA<br/>VIBRACIONES<br/>CIMIENTOS NO RIGIDOS
<br/><br/><label>Universal Decimal Class. No.: </label>621.548