Abstract: Deformations of aerospace structure parts during NC machining decrease accuracy. Thin-walled arc workpieces suffer more seriously as there are more uncertainty and comp- lexity in their machining and alignment. Fixture layout can influence the workpiece machining deformation by changing the rigidity of fixture-workpiece system. A model for reducing elastic deformation in machining through optimal placement of fixture clamps around the workpiece, is presented. The layout optimization model which is developed and carried out by FEM is shown to improve the overall workpiece deformation and distribution condition.

Key words: Finite element, Fixture, Machining deformation, Optimization