PSI - Issue 42

Harry O. Psihoyos et al. / Procedia Structural Integrity 42 (2022) 299–306 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. Geometry and dimensions of IN625 single cantilever beam.

3. Modellingprocedures 3.1. Thermomechanical modelling approach

ANSYS 2020R2 finite element commercial software package was employed for the simulationof the SLM process. The emphasis of presented modelling approach is placed on the prediction of residual stresses and strains of large parts. To this end, an abstractive method was utilized in which a uniform heat input is applied on an entire layer to neglect the modelling of laser scan passes and make the simula tion in part sca le feasible. Each layer is heated uniformly a t the melting temperature of the processedAMmetallic material. Thermomechanical analysis wasconsisted of a nonlinear transient thermal and anelastoplastic mechanical analysis performed in uncoupled way. Element birth and death was used to model the layer deposition. Transient thermal analysis was comprisedof two steps, thegradual heatingof each layer a t themelting temperature and the subsequent coolinga t thechamber environment temperature. Thepredicted temperature fields were importedas an input into the mechanical analysis to estimate the layer expansion during the heating step and layer shrinkage during the cooling step for each layer, making the residual stresses anddistortions arise as result of subsequent newlayer expansion and contraction. The schematic description of the modellingapproach is presented in the Fig. 2.

Figure 2. Schematic description of the presented thermomechanical modelling approach.