Zhang, L., 2015. Study and application of properties equivalent algorithm for composite wind turbine blade based on strain energy method.

To simplify the modeling and improve calculating efficiency of wind turbine blade, properties equivalent method of composite laminate based on strain energy method is put forward. To take representative volume element of composite as research object, basing on the two-dimension strain energy method, the equations set, which shows the relationship between equivalent stiffness matrix coefficient of composite properties and strain energy of RVE, is deduced on the three-dimension strain energy method through utilizing strain energy conservation theory and transforming of different strain energy formula. And the equation set is in accordance with the stress and strain field of RVE is the same as that of homogeneous equivalent unites under certain conditions. Then energy expression of properties equivalent stiffness matrix for composite is given. Turning the stiffness matrix into compliance matrix, the equivalent properties parameters of composite laminated plate can be obtained. Additionally, properties equivalent algorithm is applied to tri-axial composite laminated plate [0°, ±45°], and the calculating results are agreed with the measured ones. Meanwhile, properties equivalence along the longitudinal and thickness direction of 1.5 MW blade is done respectively. After comparing the results of structural analysis of the blade root for layered element model and equivalent model, the feasibility and effectiveness of the proposed algorithm can be well proved.