Thermo-mechanical analysis of Wire and Arc Additive Layer Manufacturing processon large multi-layer parts

摘要

Wire and Arc Additive Layer Manufacturing (WAALM) is gaining increasingpopularity as the process allows the production of large custom-made metalworkpieces with high deposition rates. The high power input of the weldingprocess, causes significant residual stress and distortion of the workpiece.This paper describes the thermo-mechanical behaviour of the multi-layer wallstructure made by the WAALM process. A 3D thermo-elastic–plastic transient modeland a model based on an advanced steady-state thermal analysis are employed inthis study. This modelling approach shows a significant advantage with respectto the computational time. The temperature simulations and distortionpredictions are verified by comparing with the experimental results from thermo-couples and laser scanners, while the residual stresses are verified with theneutron diffraction strain scanner ENGIN-X. The stress across the deposited wallis found uniform with very little influence of the preceding layers on thefollowing layers. The stress redistributed after unclamping with a much lowervalue at the top of the wall than at the interface due to the bending distortionof the sampl