Accession Number : AD0737285

Title :   Ballistic Vulnerability of Boron/Epoxy Double-Wall Drive Shafts

Descriptive Note : Final rept. Feb-Jun 1971

Corporate Author : UNITED TECHNOLOGIES CORP STRATFORD CT SIKORSKY AIRCRAFT DIV

Personal Author(s) : Welge, Robert T ; Veit, Frank H

PDF Url : AD0737285

Report Date : Oct 1971

Pagination or Media Count : 45

Abstract : Seven boron/epoxy double-wall shafts were ballistically impacted while under torque loads ranging from 7,500 to 12,300 in.-lb. Projectile velocities ranged from 1,540 to 2,500 fps. Static residual strength tests were then conducted. Three aluminum shafts were tested similarly for comparison. The residual strength of the boron/epoxy shafts was approximately 8,000 in.-lb, which is about one-third the ultimate strength of an undamaged tube. The aluminum shafts exhibited residual strengths of 22,000 to 32,000 in.-lb, which would be sufficient to carry expected flight loads. This program has shown that plus or minus 45 boron/epoxy sandwich drive shafts exhibit much lower residual strengths after ballistic damage than do the conventional aluminum shafts, and that design improvements would be required if the boron/epoxy shafts are to be acceptable in a ballistic environment.

Descriptors :   *AMMUNITION DAMAGE, *COMPOSITE MATERIALS, *DRIVE SHAFTS, BORON, EPOXY RESINS, HELICOPTERS, IMPACT TESTS, SANDWICH CONSTRUCTION, VULNERABILITY

Subject Categories : Machinery and Tools
      Armor

Distribution Statement : APPROVED FOR PUBLIC RELEASE