Mechanical modeling and stress suppression on high loading swept blade

The rules of effects of configuration on blade stress are key to high loading swept blade stress optimization. A mechanical model of blade with characteristic parameters of sweep and torsion was constructed. Effects of blade sweep and torsion on stress distribution were studied. It turns out that the additional moment caused by sweep is closely related to the location of blade section centroid. Extreme moment is most likely to appear in the leading and trailing edge of the blade profile and the middle of the suction surface. The additional torque caused by torsion gradually increases from blade tip to root. The torque turns negative when the torsion ration is small and it decreases the blade torsion. For typical swept blade, the stress level is mainly determined by the radial force while the stress distribution is determined by the additional moment and torque. In certain blade profile condition, the effects of additional moment and torque could be offset by sweep configuration modification, and the peak value of the stress could be reduced by more than 30%.