Accession Number : ADA184187

Title :   Preliminary Structural Design of Composite Main Rotor Blades for Minimum Weight.

Descriptive Note : Technical paper,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER

Personal Author(s) : Nixon,Mark W

PDF Url : ADA184187

Report Date : Jul 1987

Pagination or Media Count : 28

Abstract : A methodology is developed to perform minimum-weight structural design for composite or metallic main rotor blades subject to aerodynamic performance, material strength, autorotation, and frequency constraints. The constraints and load cases are developed such that the final preliminary rotor design will satisfy U.S. Army military specifications. In addition, the methodology uses design variables which can take advantage of the versatility of composite materials. A minimum-weight design is first developed subject to satisfying the aerodynamic performance, strength, and autorotation constraints for all static load cases. The minimum-weight design is then dynamically tuned to avoid resonant frequencies occurring at the design rotor speed. With this design methodology, three rotor blade designs were developed based on the geometry of the UH-60A Black Hawk titanium-spar rotor blade. The first design is of a single titanium-spar cross section, which is compared with the UH-60A Black Hawk rotor blade. The second and third designs use single and multiple graphite/epoxy-spar cross sections. These are compared with the titanium-spar design to demonstrate weight savings from use of this design methodology in conjunction with advanced composite materials.

Descriptors :   *ROTOR BLADES, *COMPOSITE MATERIALS, STRENGTH WEIGHT RATIO, PERFORMANCE(ENGINEERING), AERODYNAMIC LOADING, AUTOROTATION, FATIGUE(MECHANICS), HELICOPTERS, TITANIUM, FLUTTER

Subject Categories : Laminates and Composite Materials
      Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE