Composite propeller's strain modal and structural vibration performance

The natural frequency and displacement strain modal's vibration mode is comparative studied using validated finite modal algorithm and strain modal experiment, the result showed that the deviation of tested and calculated first three natural frequency of copper and carbon fiber propeller is within 3% and 12%.The carbon fiber propeller has smaller natural frequency, similar strain modal and four times structure damping compared with copper propeller.Further calculation of the wet modal of two propellers, the first four wet modal natural frequency of copper propeller reduced 18%~33% compared with the corresponding dry modal, while the carbon fiber propeller's reduction is 54%~64%.More research on vibration performance of propeller is carried out, the fiber orientation beneficial for vibration attenuation is obtained, the total acceleration level of optimized carbon fiber propeller is 2 dB less than the tested carbon fiber propeller.