Abstract
As a helicopter blade generates lift, it experiences a flapwise bending moment. If flap-torsion coupling is present, this bending moment generates a twist along the length of the blade, affecting the angle of attack of the blade and the amount of lift produced. Flap-torsion coupling is therefore an important effect in the aeroelastic behaviour of any aerodynamic lifting surface and is of particular interest in helicopter blade design. Other literature presents work that derives the cross sectional stiffness terms from the beam stiffness matrix by applying kinematic constraints and constitutive equations. In so doing, a number of assumptions are made about the behaviour of a rotor blade cross section. The work presented here is only concerned with the coupling between flap bending and torsion. The flap-torsion coupling is therefore derived by calculating the laminate strains throughout the section due to the applied curvature, and summing of moments of shear stress about the centre to give the resulting moment on the section. This approach enables substructures in the blade section to be modelled and shows good agreement with finite element results, and is a useful tool for studying the effects of varying different design features upon the flap-torsion coupling of the cross section.
Original language | English |
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Pages (from-to) | 184-210 |
Number of pages | 27 |
Journal | Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference |
Volume | 1 |
Publication status | Published - 2004 |
Externally published | Yes |
Event | Collect. of Pap. - 45th AIAA/ASME/ASCE/AHS/ASC Struct., Struct. Dyn. and Mater. Conf.; 12th AIAA/ASME/AHS Adapt. Struct. Conf.; 6th AIAA Non-Deterministic Approaches Forum; 5th AIAA Gossamer Spacecraft Forum - Palm Springs, CA, United States Duration: 19 Apr 2004 → 22 Apr 2004 |