In traditional 3D variation simulation (stack-up’s) it is common to consider that the parts are rigid. However, often in production forces are applied manually or by different fixturing solutions to assure that requirements on offset are fulfilled before welding parts together in an assembly. This causes the parts to bend and rigid analysis is therefore not valid. Depending on assembly sequences and geometry variation of incoming material, different fixturing forces need to be applied from component to component to assure the right fit in the seam before welding. It may even be necessary to use active fixturing where the forces are varying during the welding process. The welding process itself also contributes with variation that needs to be considered in order to fulfil geometrical requirements.

This project proposed a novel way to combine variation and welding simulation to support the design of future welding fixtures for aircraft engine components. Non-rigid Geometrical Variation Simulation were further developed to optimise locator and support positions in order to minimise geometrical variation in the weld gap and also take fixturing forces into consideration. Computational Welding Mechanics simulations with integrated control functions were further developed to prescribe fixturing forces for maintaining specific tolerances ahead of the weld for a stable weld process.

The simulation areas were combined and integrated to support the design of a physical welding fixture suitable for fabrication of aircraft engine components. The results were demonstrated virtually and physically.