Author: Thomas Carne, Arlo NordPublication: Sandia National LaboratoriesYear Published: 1982 A testing technique has been developed to measure the modes of vibration of a rotating vertical axis wind turbine. This technique has been applied to the Sandia 2-m turbine, where the changes in individual modal frequencies as a function of the rotational speed have been…
Author: James Lauffer, Thomas Carne, Thomas AshwillPublication: Sandia National LaboratoriesYear Published: 1988 In the design of large, flexible wind turbines subjected to dynamic loads, knowledge of the modal frequencies and mode shapes is essential in predicting structural response and fatigue life. During design, analytical models must be depended upon for estimating modal parameters. When turbine…
Author: Thomas Carne, Donald Lobitz, Arlo Nord, Robert WatsonPublication: Sandia National LaboratoriesYear Published: 1982 A finite element procedure, which includes geometric stiffening, and centrifugal and Coriolis terms resulting from the use of a rotating coordinate system, has been developed to compute the mode shapes and frequencies of rotating structures. Special application of this capability has…
Author: Todd Griffith, Randy Mayes, Patrick HunterPublication: Sandia National LaboratoriesYear Published: 2010 A simple modal test to determine the first tower bending mode of a 60 kW (82 feet tall) vertical axis wind turbine was performed. The minimal response instrumentation included accelerometers mounted only at easily accessible locations part way up the tower and strain…
Author: Thomas Carne, D.R. Martinez, S.R. IbrahimPublication: Sandia National LaboratoriesYear Published: 1983 A new testing technique and the Ibrahim time domain (ITD) modal identification algorithm have been combined, resulting in a capability to estimate modal parameters for rotating blade systems. This capability has been evaluated on the Sandia two-meter, vertical-axis wind turbine. Variation in modal…