Dynamic frequency analysis method of wind turbine blade and design method

A dynamic frequency analysis method of a wind turbine blade and a design method comprise the following steps: according to each parameter under a blade stationary state, carrying out a blade structure design and acquiring a structural rigidity and a natural frequency in the blade static state; analyzing and adjusting the blade structure till the natural frequency satisfied a requirement; according to a blade operation speed, calculating a centrifugal inertial load, applying the inertial load to the blade, analyzing and assessing a non-linear influence degree of the structure and calculating the changes of the structural rigidity under the influence; using the changed structural rigidity to recalculate and analyze the natural frequency of the blade. Because the non-linear influence is considered in the invention, the natural frequency of the operation state under an effect of a centrifugal force can be accurately pre-estimated. According to the design requirement, assessment is performed to the frequency and the blade structure is adjusted till the blade frequency satisfies the requirement. The designed blade structure can be helpful for guaranteeing the safety operation of the wind turbine blade and a set under the designed state.