A METHOD BASED ON CLASSICAL LAMINATION THEORY TO CALCULATE STIFFNESS PROPERTIES OF CLOSED COMPOSITE SECTIONS

Structural deformation ofcomposite wind turbine blades affect the aerodynamic performance of the rotor. To design better blades in terms of efficiency, aerodynamic performance and load mitigation, it is crucial to understand how blades act under operational loads. An interdisciplinary research should be conducted including composite structures and aerodynamics to analyze this interaction. This article focuses on the structural part and explains an easy to apply method to define sectional properties of a closed composite section. The method is based on Classical Lamination Theory (CLT) and it is assumed that the blade is a thin walled structure. Stress concentration and warping effects are ignored. During preliminary design phase, this method is useful to calculate bending and torsional stiffness values based on different lamination parameters and materials, it can also be used to investigate bending-torsion coupling effects. This article also includes parametric studies on NACA profiles using the method explained. This is the first phase of a study investigating aero-structure interaction in wind turbine blades and its effects on rotor performance.

KAPALI KOMPOZİT KESİTLERİN KATILIK ÖZELLİKLERİNİ KLASİK LAMİNASYON TEORİSİ YARDIMIYLA HESAPLAYAN BİR YÖNTEM

Kompozit rüzgar türbini kanatlarının deformasyonlarırotor aerodinamik performansını etkilemektedir.Kanatlarda daha yüksek verimlilik, iyi aerodinamik performans vemekanikyüklerin azaltılması için operasyonel yükler altında kanat davranışının anlaşılması önem arz etmektedir. Bu etkileşimi anlayabilmek için kompozit yapılar ve aerodinamik alanlarında disiplinlerarası bir çalışma yapılmasıgereklidir. Bu makale yapısal tarafa odaklanmıştır ve kapalı kompozit bir kesitin katılık özelliklerinin hesabı için uygulaması kolay bir yöntem gösterilmiştir. Yöntem, Klasik Laminasyon Teorisi (KLT) tabanlıdır ve kesitin ince cidarlı olduğu kabul edilmiştir, gerilme yığılmaları ve çarpılma ihmal edilmiştir. Ön tasarım aşamasında farklı laminasyonlar ve malzemeler ile eğilme ve burulma katılıkları hesaplanabildiği gibi eğilme-burulma etkileşimi de incelenebilmektedir. Makalede bir NACA profili üzerinde bahsedilen yöntemle çeşitli çalışmalar yapılmıştır. Bu makale türbin kanatlarında hava-yapı etkileşimi ve rotor performansına etkilerini irdeleyen bir çalışmanın ilk fazını kapsamaktadır.

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