Dynamic strain test of blower blade based on digital image correlation technology

Aiming at the crack or fracture problem of blower blade caused by large deformation in resonance, based on the principle of binocular stereovision and digital image correlation method, combined with the theory of vibration, the deformation and dynamic strain of small fan blade during vibration were studied. The results show that the maximum strain of the blade was located at the blade root, and the overall strain of the blade alternated with the excitation of sinusoidal vibration. Compared with the strain measured by the strain gauge method and the displacement measured by the laser vibrometer, the relative errors of the strain and displacement measured by the VIC-3D digital image correlation method at the blade root were about 4. 0% and 3. 5%, respectively, this measurement method was easy to operate and has high measurement accuracy.