Accession Number : ADA305560

Title :   Impact Resistance of Current Design Composite Fan Blades Tested Under Short-Haul Operating Conditions.

Descriptive Note : Interim contractor rept. Jul 72-Jun 73,

Corporate Author : GENERAL ELECTRIC CO EVENDALE OH AIRCRAFT ENGINE GROUP

Personal Author(s) : Steinhagen, C. A. ; Salemme, C. T.

PDF Url : ADA305560

Report Date : JUL 1973

Pagination or Media Count : 67

Abstract : Boron/epoxy and graphite/epoxy composite blades were impacted in a rotating whirligig facility with conditions closely simulating those which might be experienced by a STOL engine impacted with various foreign objects. The tip speed of the rotating blades was 800 feet per second. The blades were impacted with simulated birds, real birds, ice balls, and gravel. Strain gages, accelerometers, high speed movies, TTUCS (Through Transmission Ultrasonic C-Scan) measurements and sonic velocity measurements provided data on the extent and mode of impact damage. The results of composite blade impact tests were compared with a titanium blade tested under similar conditions. Delamination of the composite airfoil occurred when impacted with a 6 ounce bite from a 12 ounce bird. Both composite blades broke off at the root when impacted with a 12 ounce bite from a 28 ounce bird. Neither composite material indicated a clear superiority over the other. Blades made from both composite materials showed more damage than the titanium blades. These data are the result of an eleven month testing effort extending from July 1972 to June 1973. (AN)

Descriptors :   *IMPACT TESTS, *GRAPHITE EPOXY COMPOSITES, *SHORT TAKEOFF AIRCRAFT, STRESS STRAIN RELATIONS, VIBRATION, SURFACE ANALYSIS, NONDESTRUCTIVE TESTING, AIRCRAFT ENGINES, ACCELEROMETERS, DAMAGE ASSESSMENT, FIBER REINFORCED COMPOSITES, COMPOSITE STRUCTURES, FAN BLADES, AIRFOILS, IMPACT STRENGTH, KINETIC ENERGY, STRAIN GAGES, TITANIUM, BORON, FOREIGN OBJECT DAMAGE, FAILURE(MECHANICS), ROTATION, DELAMINATION, CYCLIC LOADS, MOMENTUM TRANSFER, IMPACT ACCELERATION, HIGH SPEED PHOTOGRAPHY, CENTRIFUGAL FORCE, BLADE TIPS.

Subject Categories : Laminates and Composite Materials
      Mechanics
      V/STOL

Distribution Statement : APPROVED FOR PUBLIC RELEASE