Analyses and design tool for the prediction of structural failure of current and future composite wind turbine blades

A computer code was developed which models the aeroelastic-structural response of arbitrary wind turbine blades undergoing gust loading. The code couples a three-dimensional, time-domain, unsteady aerodynamic analysis with a geometric, nonlinear, finite element model of a laminated composite structural blade to predict the response of wind turbine blades. The full aerodynamic loading is accounted for by rapidly tracking the unsteady, 3-D, vortex filament wake shed behind each blade of the turbine. The program also makes estimates of the nonlinear aerodynamic loading in the both the pre- and post-stall regimes. In order to make it an effective design tool, the program can accept arbitrary blade geometries including user specified airfoil sections, taper ratio, blade twist, number of blades, laminate stacking sequence, and mass and material properties. In coupling the aerodynamics with the structural model, estimates of large blade deflections and stresses can be made. The program has been compared with experimental results of the Storm Master Turbine and showed good agreement of both the aerodynamics and the structural performance. The code can be used as a design tool handling virtually any blade geometry and gust loading.