Abstract:
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A reliable computational framework for the simulation of additive manufacturing
by blown powder is crucial for its profitable use in the industrial
world. Therefore, this Master Thesis addresses a validation of an in-house
finite element software comparing numerical results with campaign data.
This data is obtained at SKLSP laboratories in China where a Laser Solid
Forming machine is employed to fabricate metal parts directly from CAD
models. Additionally, a sensitivity analysis is performed in order to acquire
a better knowledge about the influence of material properties on the results.
The numerical simulation of additive manufacturing involves the interaction
of thermal, mechanical and metallurgical phenomena. For this reason,
a large number of material properties are studied in this work. An
exhaustive set of simulations has been performed varying several mechanical
parameters, such as Poisson’s ratio, Young’s modulus or viscosity, and
studying the response in terms of vertical displacements. In an orderly way,
the results were stored and plotted to, subsequently, be compared with the
experimental data in the calibration and with each others in the sensitivity
analysis.
The experimental calibration has demonstrated a notorious agreement
with the campaign evidence after two major changes: suitable use of Poisson’s
ratio temperature dependent values and the introduction of a viscoelastic
material response in the constitutive model. The sensitivity analysis
has provided a deeper understanding of the phenomenon, placing plasticity,
visco-elasticity, and phase change as the main mechanisms which influence
the simulation. |