Development of a Graphite Horizontal Stabilizer.

Testing of graphite-epoxy composite beam and box-beam components is completed and the test results are interpreted to indicate design modifications needed in the graphite- epoxy composite stabilizers. Theoretical bending and torsional deflections of the box-beam acompared favorably with test results. Allowable stresses in xompression, shear, tension, and bearing were measured and deduced from test results and used to re- assess margins-of-safety in the stabilizer design. Design modification options to eliminate the negative margins-of-safety involved the local reinforcing of the upper skin panel or the use of bonding in additon to bolting for attachment of the upper panel. After evaluation of the design options, the use of bolting and bonding was selected on the basis of reduced weight, increased strength and reliability, and minimum impact on detail design, tooling, schedule and cost. Author, modified-PL