Abstract
Rotating beams are used to model various aerospace and mechanical structures like helicopter blades, wind turbines, gas turbine, propeller blades, etc. The long and slender beams are modelled using the Euler-Bernoulli beam theory (EBT). Whereas the short and thicker beams are usually modelled using the Timoshenko beam theory (TBT) in order to incorporate the effects of rotary inertia and shear deformation. This paper focuses on the free vibration analysis of axially inhomogeneous and nonuniform rotating beams considering the Timoshenko-Ehrenfest slope-inertia model (TESIM) as the governing equation. The TESIM governing equation is obtained by modifying the rotational term in the kinetic energy expression of the original Timoshenko beam theory. To solve the TESIM equation finite element method has been used. Natural frequencies are then calculated for different material and geometric non-uniformities along the beam axis, and for various boundary conditions.
