Dynamic stability of spinning pre-twisted sandwich beams with a constrained damping layer subjected to periodic axial loads

The dynamic stability problems of spinning pre-twisted sandwich beams with a constrained damping layer subjected to periodic axial loads are studied by using the finite element method. The complex modulus representation is used for the viscoelastic material. The gyroscopic effects for small perturbations are linearized as a skew symmetric damping matrix. The effects of pre-twisted angles and spinning speeds on unstable regions are studied. The influences of the core thickness, shear parameter, core loss factor and stiffness of constraining layer on the unstable regions are also discussed.