Dynamic stability of a rotating asymmetric cross-section blade subjected to an axial periodic force

The finite element method is applied to study the static and dynamic stability of an aerofoil cross-section rotating blade subjected to an axial periodic force. The effects of coupling due to the center of flexure (shear center) distance from the centroid, rotational speed, stagger angle and disk radius on the stability are considered. Critical load parameters are calculated and dynamic instability regions of the blade with different reference values are illustrated graphically. The numerical results indicate that the coupling effect is very important in the third and fourth modes depending on d_Y distance. The increase in stagger angle makes the blade less stable. However, the increase in rotational speed and disk radius make the blade more stable.