Design of vanes for exposure to vibratory loading

Disclosed are methods for designing vanes that, in use, are expected to be exposed to vibratory loading, in particular rotor or stator vanes for aero engines or turbomachinery. A quantitative characteristic (modeshape) is used which is a measure of correlation between the excitation force to which the vane is to be subjected in use and a vibrational mode of the vane, corresponding to a characteristic frequency of the excitation. The modeshape of the first design is determined. Then the first design is modified to give a second design, by one or more of leaning, sweeping or twisting the blade design, or by altering the local shape of the design, or by altering the material of the design. Then the modeshape of the second design is determined. The design modification gives rise to a reduction in the forced response levels.