Design And Structural Studies Of Composite Wind Turbine Blade Using Finite Element Method

The blade is considered as the most critical component in a wind turbine system whichnowadays is being manufactured using polymer matrix composite materials, in a combinationof monolithic and sandwich structures. Composite materials satisfy complex designconstraints such as lower weight and proper stiffness, while providing good resistance to thestatic and dynamic loading.A composite9-meter long wind turbine blade has been designed on the basis of BladeElement Theory (BET) and finite element analysis (FEM) has been performed by usingcommercial code ANSYS finite element package. Various design parameters for a blade suchas material properties, laminate lay-up, skin thickness, ply orientation, internal spar etc. havebeen determined iteratively to get optimal blade structural design. Classical laminate theoryand sandwich construction principles are utilized in the development of the material layup.NREL S-series airfoils with different chord thickness are used along current blade cross-sections. Two design cases were analyzed, involving differences in materials, stackingsequence, ply orientations and lamination thickness.Material selections for wind turbine blade design are also an important consideration forblade design and fabrication. Glass fibers are traditionally being used as a basis material for windturbine blade manufacturing. I also would like to address the advanced use of carbon fibers in awind turbine blade through design, manufacturing and structural performance in order to havereduced weight and increased stiffness for the blade as an alternative material. It is observedthat, there is a substantial weight saving (in the current case almost11%) with the use of cost-effective carbon/glass hybrid material. One of the focuses is on the structural static strength ofwind turbine blades loaded in flap-wise direction and methods for optimizing the blade cross-section to improve structural and manufacturing characteristics. An Eigen value bucklinganalysis will also be carried out in order to confirm the blade to be sound and stable undervarious load conditions. Moreover, the natural frequencies and modal shapes of the rotorblade were calculated and plotted for defining dynamic characteristics.