Damage evolution prediction of wind turbine blades

A new model based on stiffness degeneration was developed to predict the damage evolution of wind turbine blades. The actual ply scheme and working conditions of blades, representing damage by the rules of stiffness degeneration and judge failure by strength degeneration in each layer. Considering the anisotropy of wind turbine blade material, three scalars were used to describe damage in different directions. Through analyzing the damage process, the fatigue damage and cumulative fatigue damage rules were defined, the stiffness reduction formulas of each ply were given, through material experiment, the parameters in stiffness reduction formulas have gotten. A real wind turbine blade fatigue test process was simulated; the calculation results are in agreement with the test results.