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Title:
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PRODETO-computer program: theory and program structure
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Author(s):
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Published by:
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Publication date:
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ECN
Solar Energy
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1998
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ECN report number:
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Document type:
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ECN-C--97-093
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ECN publication
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Number of pages:
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Full text:
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55
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Download PDF
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Abstract:
Within the project PRODETO computer tools were developed by which thestructural reliability of fatigue loaded wind turbine blades can be analysed.
The PRODETO software consists of the programs RAINSTAT and FATSTAT and the
source code damage.for which has to be linked to a commercially available
computer program for component reliability analysis, such as RELIABOI and
STRUREL. The theoretical background and the structure of the software are
presented in this report. The current version of the software is mainly
focused at fatigue damage due to the flapwise bending moment in the blade.
Because the flapwise bending moment often appears to have a distribution
which resembles a Weibull distribution it is natural to start out with a
Weibull distribution and subject it to a slightly non-linear transformation
to something that fits well with the measured or calculated data. A number of
such models are available but the main problem is that they are very computer
intensive. As the 3-parameter Weibull distribution provides a good fit to the
data and does not cause a high computer load it was chosen for use in the
PRODETO software. Furthermore, a procedure for the calibration of the partial
safety factors for fatigue loading is outlined for a site-specific wind
turbine. This procedure is taken from Part 2 of the EWTS-I project
'Calibration of safety factors'. As the requirement generally turns out to be
on the product of the load factor gammaf and the material factor
gammam, the calibration results in the required value for
gammafgammam when the safety level is prescribed. A method is presented
to determine a particularly robust set of partial safety factors among the
infinite number of sets that fulfill the requirement. 22 refs.
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