Accession Number : ADA307365

Title :   Impact Resistance of Fiber Composite Blades Used in Aircraft Turbine Engines.

Descriptive Note : Contractor rept.,

Corporate Author : PRATT AND WHITNEY AIRCRAFT GROUP EAST HARTFORD CT

Personal Author(s) : Friedrich, L. A. ; Preston, J. L., Jr

PDF Url : ADA307365

Report Date : MAY 1973

Pagination or Media Count : 152

Abstract : Resistance of advanced fiber reinforced epoxy matrix composite materials to ballistic impact was investigated as a function of impacting projectile characteristics, and composite material properties. Ballistic impact damage due to normal impacts, was classified as transverse (stress wave delamination and splitting), penetrative, or structural (gross failure). Steel projectiles were found to be >gelatin >ice projectiles in causing penetrative damage leading to reduced tensile strength. Gelatin and ice projectiles caused either transverse or structural damage, depending upon projectile mass and velocity. Improved composite transverse tensile strength, use of dispersed ply lay-ups, and inclusion of PRD-49-1 or S Glass fibers correlated with improved resistance of composite materials to transverse damage. In non-normal impacts against simulated blade shapes, the normal velocity component of the impact was used to correlate damage results with normal impact results. Stiffening the leading edge of simulated blade specimens led to reduced ballistic damage, while addition of a metallic leading edge provided nearly complete protection against 0.64cm diameter steel, and 1.27 cm diameter ice and gelatin projectiles, and partial protection against 2.54 cm diameter projectiles of ice and gelatin.

Descriptors :   *FIBER REINFORCED COMPOSITES, *FAN BLADES, *IMPACT STRENGTH, *GAS TURBINES, VELOCITY, TENSILE STRENGTH, AIRCRAFT ENGINES, COMPOSITE MATERIALS, LAMINATES, PROJECTILES, IMPACT TESTS, COMPOSITE STRUCTURES, GRAPHITE, STRAIN(MECHANICS), PENETRATION, ICE, TERMINAL BALLISTICS, GLASS FIBERS, LEADING EDGES, BORON, FOREIGN OBJECT DAMAGE, FAILURE(MECHANICS), DELAMINATION, GELATINS, AMMUNITION DAMAGE.

Subject Categories : Laminates and Composite Materials
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE