Accession Number : ADA307360

Title :   Impact Resistance of Composite Fan Blades.

Descriptive Note : Contract rept.

Corporate Author : GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE BUSINESS GROUP

PDF Url : ADA307360

Report Date : DEC 1974

Pagination or Media Count : 143

Abstract : This report presents the results of a program to determine the impact resistance of composite fan blades subjected to foreign object damage (FOD) while operating under conditions simulating a short takeoff and landing (STOL) engine at takeoff. The full-scale TF39 first-stage fan blade was chosen as the base design for the demonstration component since its configuration and operating tip speeds are similar to a typical STOL fan blade and several composite configurations had already been designed and evaluated under previous programs. The first portion of the program was devoted toward fabricating and testing high impact resistant, aerodynamically acceptable composite blades which utilized only a single material system in any given blade. The material systems utilized were a graphite/epoxy system (AU/PR 288) and a boron/epoxy system (4.0 mil/5505). It was determined that the blades of each material system were both capable of sustaining impact equivalent to a half bite of a 624 gram (22ounce) bird without total failure. Beyond this point, both blades broke off at the root at impact. In order to increase the blade impact capability beyond this point, several mixed material (hybrid) designs were investigated using S-glass and Kevlar as well as boron and graphite fibers. These hybrid composite blades showed a marked improvement in resistance to bird impact over those blades made of a single composite material.

Descriptors :   *FAN BLADES, *IMPACT STRENGTH, *FOREIGN OBJECT DAMAGE, *GRAPHITE EPOXY COMPOSITES, *SHORT TAKEOFF AIRCRAFT, COMPOSITE MATERIALS, LAMINATES, FIBER REINFORCED COMPOSITES, POLYAMIDE PLASTICS, COMPOSITE STRUCTURES, GRAPHITE, CARBON FIBERS, BIRD STRIKES, HYBRID SYSTEMS, LEADING EDGES, PREPREGS, EPOXY RESINS, SPECIFIC GRAVITY.

Subject Categories : V/STOL
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE