A sensitivity analysis and aeroelastic optimization for a composite hingeless rotor with a generic section is developed using an analytical approach. The design variables used in this study are the ply angles of the laminated walls of the box-beam at five spanwise elements. Aeroelastic and sensitivity analyses are based on a finite element in space and time. Optimization studies are carried out for a four-bladed, soft-inplane composite rotor consisting of a two-cell box beam spar. The objective functions are the vibratory hub loads and the vibratory bending moments; constraints are imposed on blade rotating frequencies and aeroelastic stability. The objective functions are first minimized individually and then, a multi-objective optimization is performed to minimize both the objectives simultaneously. Optimum designs for the multi-objective optimization show a reduction in the objective function of about 30 percent from the starting design; 20 percent of this reduction is due to elastic stiffness and 10 percent due to composite coupling (flap bending-torsion). As compared to the starting design, the optimum solution results in a 15-60 percent reduction of the 4/rev hub loads as well as a reduction in the peak-to-peak flap and lag bending moments of 11 and 14 percent, respectively, compared to the starting design. Starting from an initially infeasible starting design with a 3 percent requirement on lag mode damping, the optimum solution with composite chordwise bending-torsion coupling results in an increase in lag mode damping of over 200 percent compared to the starting design.
Multi-objective optimization of a composite helicopter rotor
Optimierung in vielerlei Hinsicht eines Hubschrauber-Drehflügels aus Verbundwerkstoff
1994
21 Seiten, 12 Bilder, 3 Tabellen, 24 Quellen
Aufsatz (Konferenz)
Englisch
British Library Conference Proceedings | 2022
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