Vibration equation and frequency computation of an aero-engine rotor blade

During the running process of an aero-engine, the working conditions of the blade are extremely poor. Aerodynamics and mechanical force would inevitably excite the blade continuously and cause its forced vibration. Especially when the load frequency equals the dynamic frequency of the blade, resonance will occur, which can increase the stress evidently and even damage the blade. Therefore it is particularly important to learn about the natural frequency of the blade at different rotational speeds. Based on the force analysis of the blade, we establish its free vibration equation by introducing a deformation coefficient. And then we develop a numerical method to calculate the static and dynamic frequencies of the blade, with the help of Ritz-Galerkin method. Compared with traditional methods, the present method is more convenient and closer to the actual condition and its results match well with the experimental data, which supplies a reasonable method of engineering importance.