Structural Optimization of a Cantilevered Rotating Beam

Abstract

A basic study concerning the structural optimization of a rotor blade subject to steady combined loadings is conducted. The combined loadings are assumed to be composed of distributed axial and lateral loadings which are simulating the centrifugal force and airloadings for a rotor blade in hover. To simplify the problem, the blade is modeled as a cantilevered rotating beam with the plane tapered cross section. The minimum deflection problem of the cantilevered rotating beam is formulated as an optimization problem involving inequality constraints and solved using optimal control methodology. Optimum area distributions are determined numerically for typical combinations of combined loadings and effects of the centrifugal force on the optimum solutions are discussed. Numerical results reveal clearly the important role of the axial loading on the optimum solution and inclusion of the centrifugal force to the structural optimization of the rotor blade should be essential.