Semiactive control of a shape memory alloy hybrid composite rotating shaft

In this paper the technique of the dynamic stability analysis proposed for the conventional laminated structures is extended to the activated shape memory alloy (SMA) hybrid rotating shafts under the time-dependent compressive axial loading. The influence of the activation through the change of the temperature on the dynamic stability domains is examined. Changing with the temperature the Young's modulus of SMA fibers enters into a global stiffness parameter of the shaft. Thermally induced membrane forces in SMA fibers and changing with temperature damping coefficient also modify shaft dynamic equations. The activated SMA hybrid shaft is treated as a beam-like structure. The thin-walled composite shaft is flexible thus it should be supported on the both ends in order to avoid large deflections. By using the standard stability technique we arrive at the effective sufficient criterion of the dynamic and almost sure stochastic stability. The stability regions are given as functions of the loading characteristics, the external damping coefficient, the lamination angle, and the properties of the shaft material. The results indicate that the global activation causes an increase of the critical (admissible) axial force both for the glass–epoxy/NiTi–epoxy and for the graphite–epoxy/NiTi–epoxy hybrid shafts.