Author(s)

H. Zhang, A. Maheri, A. Daadbin & P. Hackney

Abstract

An analytical model capable of predicting the induced deformation due to the presence of bend-twist and stretch-twist elastic couplings in multi-cell closed thin walled beams with arbitrary cross-sections is presented. For various structural and material configurations, the results obtained by the developed model are compared with the results of the finite element analysis. It is shown that the developed analytical model provides reasonable accuracy in predicting induced twist. The developed model is implemented in an aero-structure simulation environment for simulation of wind turbines utilising adaptive blades. Keywords: thin-walled beam, multi-cell closed thin walled beams, adaptive blades, elastic coupling, bending-twist coupling, wind turbine composite blade. 1 Introduction Fibrous composite materials have been broadly used in aeronautical and aerospace structures due to their proven advantages, such as high strength-weight ratios. One particular application of these materials is in fabricating smart and adaptive aerodynamic lifting surfaces such as wind turbine adaptive blades and aircraft smart wings. An adaptive blade acts as an open-loop controller that senses the wind velocity or rotor speed variations and adjusts its aerodynamic characteristics accordingly to improve the wind turbine performance. This selfcontrol system can be achieved by implementing elastic coupling in the structure of the blade. In order to determine the aerodynamic performance of adaptive blades at various loading conditions, a structural analyser is required to calculate the induced deformation of the blade. Figure 1 shows the simulation environment for wind turbines utilising this type of blades. Torsional of wind turbine adaptive blades

Keywords

thin-walled beam, multi-cell closed thin walled beams, adaptive blades, elastic coupling, bending-twist coupling, wind turbine composite blade.