Strength analysis of the conceptual model of a main rotor blade spar with actuators

Abstract

This paper concerns the conceptual design of a main rotor blade spar with actuators. A three-dimensional model of a main rotor blade is based on the preliminary geometric blade setting angle to increase the aerodynamic performance caused by different linear velocities of individual cross-sections. A modification of the blade setting angle results in a change of the angle of attack and influences the value of the lifting force in a given blade cross-section. The geometric setting angle was applied in designing both the main rotor blade spars and the blade. The overall dimensions of the blade depended on the available surface of the outmost blade airfoils. The important element of the designed spars was a cut in the form of a notch enabling the upper and lower crossbars of the designed spar to move during the operation of actuators. The FEM analysis was carried out on the parts of the designed blade spars. Three types of materials were compared in the finite element analysis. The internal stresses and displacements of the outmost edges of the crossbars were analyzed. The Catia V5 software was used for the designing work. The sections of the spars were analyzed using the Finite Element Method. The Pre/Post module of NX 12 was used for the FEM analysis. The displacement results were analyzed, which allowed us to determine their twist angle.