Objectif 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. Champ scientifique 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 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur ENERGY RESEARCH CENTRE OF THE NETHERLANDS Contribution de l’UE Aucune donnée Adresse Westerduinweg 3 PETTEN Pays-Bas Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée Participants (6) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire CIEMAT Espagne Contribution de l’UE Aucune donnée Adresse 28042 Madrid Voir sur la carte Coût total Aucune donnée GARRAD HASSAN AND PARTNERS LTD Royaume-Uni Contribution de l’UE Aucune donnée Adresse BS18 9JB Bristol Voir sur la carte Coût total Aucune donnée RISOE NATIONAL LABORATORY Danemark Contribution de l’UE Aucune donnée Adresse 4000 Roskilde Voir sur la carte Coût total Aucune donnée Stork Product Engineering B.V. Pays-Bas Contribution de l’UE Aucune donnée Adresse 1000 AJ Amsterdam Voir sur la carte Coût total Aucune donnée TECHNICAL UNIVERSITY OF DENMARK Danemark Contribution de l’UE Aucune donnée Adresse 2800 Lyngby Voir sur la carte Coût total Aucune donnée TEKNIKGRUPPEN AB Suède Contribution de l’UE Aucune donnée Adresse 19121 Sollentuna Voir sur la carte Coût total Aucune donnée