Accession Number:

ADA301222

Title:

Abrasion Behavior of Aluminum and Composite Skin Coupons, Stiffened Skins, and Stiffened Panels Representative of Transport Airplane Structures.

Descriptive Note:

Technical paper,

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s):

Report Date:

1985-11-01

Pagination or Media Count:

34.0

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.

Subject Categories:

  • Transport Aircraft
  • Metallurgy and Metallography
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE