TWI

With regard to the development of friction stir welding (FSW) processes for joining large thin walled 3D structures in aircraft fuselage applications, an investigation is presented into the "LuFo IV" machine concept, incorporating clamping, positioning, milling and welding of large flexible 3D shells within one clamping fixture, and into results for 3D welded joints of difficult-to-weld aluminium alloys. The "LuFo IV" concept comprised a combined welding/milling trolley travelling independently along a 3D bent rail system and an intelligent clamping system to guarantee part positioning within required tolerances. The process chain involved insertion and positioning of shells, preprocessing of edges, positioning of shells (zero gap), FSW of shells and unclamping of welded shells. Welding experiments were conducted for AA 6013-T4 and AW 6082-T6 aluminium alloy sheets (thickness 2 and 3 mm, respectively. The microstructures of thermomechanically affected zone and HAZ are discussed.

11th International Symposium, 17-19 May 2016, Session 3A: Robotic and Non Linear, Paper 01