Dynamic stability of laminated beams subjected to nonconservative loading

A stability analysis of laminated beam structures subject to subtangential loading, a combination of conservative and nonconservative tangential follower loads, using the dynamic criterion is performed. These loads are characterized using a nonconservativeness loading parameter. This parameter allows us to study the effect of the level of load conservativeness on the stability of laminated beams. The element tangent stiffness and mass matrices are obtained using analytical integration through the dynamic version of the principle of virtual work for laminated composites. Results for the conservative loading, for both isotropic and laminated beams, are in very good agreement with those available in the literature. For the case of partially conservative loads, results show that for both isotropic and laminated composite beams, and in the absence of damping, all values of the nonconservativeness loading parameter less than or equal to 0.5 will be governed by the divergence instability, and by flutter instability otherwise.