AAR has announced its ground-breaking application of advanced welding technology to produce light-weight multipurpose shelters (LMS) for military customers that are electromagnetic shielded to house sophisticated battlefield systems.

The technology, known as Friction Stir Welding (FSW), enables metals to be bonded in their natural state, without melting or the use of studs, or fasteners. The result is a stronger, lighter weight shelter that is EMI capable, providing added value, isolation and protection for critical in-theater military and defense equipment.

AAR is the first US manufacturer of aerospace and defense products to use friction stir welding technology in the development and production of multipurpose mobility structures.

"Through innovative application of this process, AAR has improved upon the design and durability of these critical defense structures."

"Through innovative application of this process, AAR has improved upon the design and durability of these critical defense structures," said Lee Krantz, vice president and general manager, AAR Mobility Systems.

"We believe Friction Stir Welding is a breakthrough approach to building these shelters and represents the future in welding and lightweight design. It is another way AAR remains committed to leading innovation in the industry."

Last July, the company was awarded a five-year $14m contract to provide three variations of Lightweight, Multipurpose Shelters (LMS) for the US Army. LMS is the primary platform that the army uses to house and operate command and control equipment for situational awareness and tactical support in various theaters of operation.

FSW technology was developed in 1991 at The Welding Institute (TWI) in Cambridge, England, and later gained popularity as an alternative to fusion welding technology, in which a lower strength filler material is introduced into the metal, in Sweden’s maritime industry. The technique is typically performed on aluminum and large metal pieces that are more difficult to fusion weld.

"Melting a material can actually decrease the strength of the weld," said Gil Sylva, a senior engineer in Materials and Processes who was part of the team that developed the technique at TWI in Cambridge.

"In FSW, you’re not adding anything to the metal that is lower in strength. Rotational and downward force plasticize the metal by generating friction heating, forming a joint with a grain structure that is finer than the parent metal, making for a virtually seamless and extremely strong joint."