Boeing Commercial Airplane Company, Seattle, WA
The graphite/epoxy 737 horizontal stabilizer shown in Fig. 1 features a metal elevator side-load reacting hinge at the inboard end and aerodynamic balance panels at the mid-span. Under the temperature extremes of airplane operation, the metal elevator expands and contracts about the side load reacting hinge. Because of the difference in thermal expansion between the aluminum elevator and the graphite/epoxy stabilizer, a large thermal displacement builds up along the span of the elevator. The magnitude of the displacement is such that the balance panel seals would become ineffective and friction would be excessive. Also, the clevis of the outer hinges would have to be widened considerably to accommodate the hinge displacements. Widening the hinges could result in excessive hinge-pin bending stresses.
Paper ID: CTR10651J