This paper describes the structural optimization of composite helicopter rotor blades with swept tips to minimize the B/rev vibratory hub loads in forward flight subject to frequency and aeroelastic stability constraints. The aeroelastic analysis is based on a moderate deflection finite element model that is suitable for composite rotor blades with swept tips in hover and in forward flight. Arbitrary cross-sectional shape, generally anisotropic material behavior, transverse shears and out-of-plane warping are included in the blade model. The optimization study is applied to composite blades with two-cell, hingeless configuration. Both soft-in-plane and stiff-in-plane blade configurations are analyzed. Ply orientation in the horizontal and vertical walls of the blade cross section and tip sweep and anhedral angles are selected as design variables. The optimization results obtained show that among the design variables selected tip sweep appears to be the most influential design variable. Depending on the configuration considered and objective function used, vibration reduction in vertical hub shears of the order 30 % - 50 % from the baseline can be obtained.
Structural optimization for vibratory loads reduction of composite helicopter rotor blades with advanced geometry tips
Strukturoptimierung zur Schwingungslastreduktion von Verbund-Rotoren mit fortgeschrittenen Blattspitzenformen
Journal of the American Helicopter Society ; 43 , 3 ; 246-256
1998
11 Seiten, 12 Bilder, 3 Tabellen, 34 Quellen
Aufsatz (Zeitschrift)
Englisch
Aeroelasticity and Structural Optimization of Composite Rotor Blades with Advanced Geometry Tips
British Library Conference Proceedings | 1995
|Vibratory Ice Protection for Helicopter Rotor Blades
NTIS | 1978
|British Library Conference Proceedings | 1994
|