Electromagnetic Forming of Various Aircraft Components 2005-01-3307

Electromagnetic forming (EMF) technology has been used lately for the joining and assembly of axisymmetric parts in the aerospace and automotive industries. A few case studies of compressive-type joining processes applied on both aluminum and titanium or stainless tubes for aerospace applications are presented. In the first case study, tests were conducted using 2024-T3 drawn tubes joined with a steel end fitting to form a torque tube using different forming variables including: the fitting geometry, material formability and forming power (KJ). The power setting and the fitting geometry were optimized to improve the fatigue life, torque off, and the axial load capability of the torque tube joints to drive the leading and trailing edge high-lift devices. In another case study, a new process was conceived and developed for producing a high-operating-pressure (34 MPa) hydraulic system that requires the use of thick-walled titanium or stainless steel tubing with the subsequent attachment of titanium or stainless steel end fittings. The first development feature is the design of the end fitting that not only provides adequate contact surface area at the union's conical surface-fitting interface, but maximizes front sealing integrity and the strength of the joint. Second, the developed groove geometry on the tube outside diameter and its placement enhances the strength of the EMF joint between the tube and the end fitting. This was later optimized to satisfy the burst pressure test which is conducted at four times the system operating pressure. The newly designed fittings provided leak-free connections between two joints using the standard nut, coupling and unions. The technical benefits of this new method should include reducing: the manufacturing process steps (compared to orbital welding / roller swaged / elastomeric processes), inspection process steps, and cost of production; and will also provide a highly reproducible manufacturing process to maintain the highest quality possible.