DYNAMIC STABILITY OF ROTATING COMPOSITE SHAFTS UNDER PERIODIC AXIAL COMPRESSIVE LOADS

This paper describes the dynamic behavior of a rotating composite shaf t subjected to axial periodic forces using the finite element method. Laminated composite shafts are modelled using Timoshenko beams. The nu merical results show good agreement with the reported beams models. Ef fects of static and time dependent components of axial loads on the st ability of the composite shaft are studied. This paper also investigat es the effect of the rotational speeds and the disk on the unstable re gions of the shaft. The numerical results show that for the same geome tric parameters, a steel shaft has a lower frequency than that of the composite shafts; however, the steel shaft is more stable than composi te shafts because the shaft-disk system is subjected to axial periodic forces at lower rotational speeds. Also, the effect of the gyroscopic moments makes the steel shaft more sensitive to the periodic axial lo ad than the composite one. (C) 1998 Academic Press Limited.