Abstract: For the problem that composites wind turbine blades always occurre damage, a model, which is a composite microscopic damage analysis model based on a microscopic failure criterion, is proposed. The generalized method of cells (GMC) is employed to model for unidirectional composite laminated plates with periodic microstructures. A microscopic failure criterion based Huang model is also introduced. The failure mode of fiber and matrix are characterized respectively microscopically. The progressive damage of four unidirectional composite laminated plates is simulated numerically. Static loading experiments are also carried on wind turbine blades of composite with two different states (damaged and undamaged) and the influence of the damage on the strain of the wind turbine blades is monitored by the fiber bragg grating. The strain curve get through the failure experiment of the typical unidirectional laminate is used to verify the effectiveness of the algorithm proposed. The experimental analysis shows that the carrying capacity of the composite wind turbine blades will reduce when it is damaged, and their strain curve can be used to monitor the health statement of wind turbine blades. The proposed model can accurately predict the mechanical properties and breaking strength values of unidirectional composite plates.

Key words: wind turbine blades;composite materials;generalized method of cells;damage criteria;strain;fiber bragg grating