The influence analysis of curvature on transverse vibration of multi-curved shafting based on numerical and experimental results

Shafting would be a curved status for the heavy propeller. This article addresses a numerical and experimental vibration analysis of curved shafting. In the numerical theory, the shafting is simplified as a multi-curved beam system with a tail point mass. The system model is derived based on the so-called spectro-geometric method (SGM) in which the transverse and tangential displacement over each sub-structure is invariably expressed as a modified Fourier series expansion. All the unknown Fourier coefficients are treated as a set of independent generalized coordinates and solved directly from the Rayleigh-Ritz procedure. The experimental was carried out on a laboratory-size shafting model which is curved factitiously. The numerical results show that the relationship between the frequency and the beam curvature is complex. It strongly depends on the boundary conditions. The experimental results indicate that the frequency of the shafting would decrease with the increase of the curvature compared with straight shafting.