Abrasion Behavior of Aluminum and Composite Skin Coupons, Stiffened Skins, and Stiffened Panels Representative of Transport Airplane Structures.
Abstract
A three-phase investigation was conducted to determine the friction and wear behavior of aluminum and composite materials under conditions similar to the loadings experienced by skin panels on the underside of a transport airplane during an emergency belly landing. In the first set of experiments, small skin coupons of aluminum and graphite-epoxy (Gr-Ep) were abraded in the laboratory. An abrasion test apparatus was designed which used a standard belt sander to provide the sliding surface. The test rig was equipped with a load cell to measure the frictional forces developed during abrasion. The skin-coupon specimens were abraded over a range of pressures (2 to 5 psi), belt velocities (16 to 50 mph), and belt surface textures (0.01 to 0.02 in.). The parameters chosen fall within the range of conditions considered typical of an airframe sliding on a runway surface. The effects of pressure and velocity on the wear rate and coefficient of dynamic friction were determined, and comparisons were made between the Gr-Ep and aluminum. Results of the laboratory tests indicate that Gr-Ep skin coupons have wear rates four to five times higher than aluminum and a coefficient of friction of about half that of aluminum. The second phase of the investigation involved abrading more representative skin structures, consisting of I-beams with attached skins constructed of aluminum, Gr-Ep, and glass hybrid composite. These stiffened skins were abraded on an actual runway surface over the same range of pressures and velocities as in the laboratory skin-coupon tests.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1985
- Accession Number
- ADA301222
Entities
People
- Karen E. Jackson
Organizations
- Langley Research Center