Nonlinear dynamics of a base-isolated beam under turbulent wind flow

A homogeneous continuous viscoelastic beam, describing the dynamics of a base-isolated tower, exposed to a uniformly distributed turbulent wind flow, is studied. The beam is constrained at the bottom end by a nonlinear viscoelastic device, and it is free at the top end. Aeroelastic forces are computed by the quasi-static theory. The steady component of wind is responsible for a Hopf bifurcation, and the turbulent component induces parametric excitation. The interaction between the two bifurcations is investigated. Critical and post-critical behavior is analyzed by perturbation methods. The mechanical performances of the structure are discussed to assess the effectiveness of the viscoelastic isolation system.