The influence of an initial twisting on tapered beams undergoing large displacements

The behaviour of pre-twisted and tapered beams (such as turbine or helicopter blades) is characterized by stress distributions that may be quite different from those the usual beam theory, yielding couplings among bending, twisting traction. We propose a physical–mathematical model for accounts effects pre-twist cross-sections along centre-line. centre-line undergo large displacements, while its see small warping both in- out their plane. Supposing infinitesimal strain, variational approach provides field equations, which are perturbed in terms geometric ratio shall solved numerically general. However, analytical closed-form solutions exist some cases, such isotropic with pre-twisted, bi-tapered elliptic cross-sections; they presented compared results nonlinear 3D-FEM simulations.