Abstract:

A method of finite element analysis based on modality analysis theory with equipment and ANSYS software is used to study a fan blade. According to its inherent frequency and modal shapes under different speeds,the result is figured that maximum blade deformation generally occurred at the tip or on the leading edge,and its location could be found in modal shape. After making Campbell map to analyze its vibration characteristics,there are four resonance points exist in the range of first-order and second-order. The four resonance points and the blade's rotation margins show that the fan blade meet requirement of 10% vibration margin. This method could supply theoretical basis for blade design,performance evaluation and fault diagnosis.

Key words: fan blade, modality analysis, ANSYS, Campbell map, rotation speed margin