Conventional manufacturing processes often require a large amount ofmachining and cannot satisfy the continuously increasing requirements of asustainable, low cost, and environmentally friendly modern industry. Thus,Additive Manufacturing (AM) has become an important industrial process for themanufacture of custom-made metal workpieces. Among the different AMprocesses, Wire and Arc Additive Manufacture (WAAM) has the ability tomanufacture large, low volume metal work-pieces due to its high depositionrate. In this process, 3D metallic components are built by depositing beads ofweld metal in a layer by layer fashion.However, the non-uniform expansion and contraction of the material during thethermal cycle results in residual stresses and distortion. To obtain a betterunderstanding of the thermo-mechanical performance of the WAAM process, astudy based on FE simulation was untaken in this thesis. The mechanism of thestress generation during the deposition process was analysed via a 3D transientthermo-mechanical FE model which is verified with experimental results. To becapable of analysing the thermo-mechanical behaviour of large-scale WAAMcomponents, an efficient FE approach was developed which can significantlyreduce the computational time. The accuracy of this model was validatedagainst the transient model as well as experimental measurements.With the help of the FE models studies on different deposition parameters,deposition sequences and deposition strategies were carried out. It has beenproved that the residual stresses and the distortions are possible to be reducedby using optimised deposition parameters and sequences. In addition, a robotpath generation prototype has been developed to help efficiently integrate theseoptimised process settings in the real-wold WAAM process.
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