Objective To establish a general accepted procedure how to obtain and combine all six internal blade loads in order to determine fatigue stress including design safety factors for life time predictions. In order to calculate fatigue stresses for wind turbines, a set of preliminary calculations were first performed. These included calculations of:aerodynamic power coefficient;flat moment;rotor shaft torque.Some discrepancies were found between the resuls calculated by different partners. This is probably due to the fact that different models are being used.A series of load calculations, specifically of the cumulative flat and egdewise bending moment and the rotor shaft torque spectra for the design loading conditions, were performed. Again there were discrepancies in the results possibly due to differences in wind turbulence modelling.The fatigue stress factor (FSF) was then determined for 3 chosen crosssections:rotor blade inner cross section (material steel);rotor blade outer cross section (material glass fibre reinforced plastic);rotor shaft at first bearing.The load cases normal (composed of operation, start, stop and idling) combined with 2 fault conditions (yaw and pitch) over the design pipe of the wind turbine were considered.As a preliminary conclusion it may be said that the spread in the FSF for the inner cross section is too large and reasonable for the other locations. Further assessment is necessary to draw any firm conclusions.The calculation of rotor blade loads by means of computer programmes have reached a certain degree of maturity. This is also the case with regard to design requirements imposed by licensing or equivalent authorities. Most of these requirements are stated as general conditions, such as: "that normal, extreme and faulted conditions shall be taken into account". As large size wind turbines will be designed on basis of analyses, a balanced implementation of all steps to establish fatigue stresses shall be aimed at, in order to estimate reliable life time predictions. The work procedure is directly at gaining insight and conclusive proposals with regard to the following topics in-view of its impact on the estimated design life of horizontal axis wind turbines. 1) inventory of load conditions; 2) wind input; 3) wind turbine (wind farm aspects are not considered); 4) load calculations, viz. calculation of internal load spectrum in time or frequency domain; 5) stress calculations; 6) fatigue damage model; 7) design life. Note that item 6) is not to be elaborated as a research subject belonging to this contract, but as a mean for performing sensitivity assessments. The work procedure will be based on mutual comparison of the implementation of procedures and calculation methods. Fields of science natural sciencesphysical sciencesclassical mechanicsfluid mechanicsfluid dynamicsengineering and technologyenvironmental engineeringenergy and fuelsrenewable energywind powerengineering and technologymaterials engineering Programme(s) FP2-JOULE 1 - Specific research and technological development programme (EEC) in the field of energy - non-nuclear energies and rational use of energy - (JOULE), 1989-1992 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator ENERGY RESEARCH CENTRE OF THE NETHERLANDS EU contribution No data Address Westerduinweg 3 PETTEN Netherlands See on map Links Website Opens in new window Total cost No data Participants (6) Sort alphabetically Sort by EU Contribution Expand all Collapse all CIEMAT Spain EU contribution No data Address 28042 Madrid See on map Total cost No data GARRAD HASSAN AND PARTNERS LTD United Kingdom EU contribution No data Address BS18 9JB Bristol See on map Total cost No data RISOE NATIONAL LABORATORY Denmark EU contribution No data Address 4000 Roskilde See on map Total cost No data Stork Product Engineering B.V. Netherlands EU contribution No data Address 1000 AJ Amsterdam See on map Total cost No data TECHNICAL UNIVERSITY OF DENMARK Denmark EU contribution No data Address 2800 Lyngby See on map Total cost No data TEKNIKGRUPPEN AB Sweden EU contribution No data Address 19121 Sollentuna See on map Total cost No data