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The relevant scale for mechanical modelling in additive manufacturing
technologiesSofiane Guessasma1 & Sofiane Belhabib2
1INRA, research unit BIA, Nantes, France [email protected]
2IUMR CNRS GEPEA, University of Nantes, France [email protected]
Basics of FE simulation in structural mechanics
Complex load/geometry + simple mechanical law
Complex mechanical response + simple load configuration
Complexity in both mechanical law + configuration
Fused filament (FDM)
Stereolithography
Droplet-based
Materialdiscontinuity
Source of complexity: material discontinuities
Mechanical response in additive manufacturing
Mechanical response in additive manufacturing
Mechanical response in additive manufacturing
Mechanical response in additive manufacturing
Comsol model:Handelling raster effect filament crossing sequence +45°/‐45°
Regular meshing (2.7 M dof)
Building direction
X’
Y’
Z
In‐plane (XY)
XY
Fused Deposition modelling: printing angle
Local property distribution
Topological law: Young’s modulus = 45°
= 30°= 0°
1.00
1.051.101.151.201.251.30
E (GPa)
Compression behaviour
Heteregeneous strain field
Positive strain Poisson’s expansion
Crack opening (mixed mode)
Explaining effect of raster on performance
Comsol predictions
3D imaging
CAD-based modelling:
Compression performance of
cellular structures
Comparison between FE and
experimental Young’s moduli
Strain field100 150 200 250 300 350 400100
150
200
250
300
350
400
Pre
dict
ed (M
Pa)
Experimental (MPa)
Filament-based simulation R²=0.87 Design-based simulation R²=0.46
Perfect matching
100 150 200 250 300 350 400100
150
200
250
300
350
400
Pre
dict
ed (M
Pa)
Experimental (MPa)
Filament-based simulation R²=0.87 Design-based simulation R²=0.46
Perfect matching
100 150 200 250 300 350 400100
150
200
250
300
350
400
Pre
dict
ed (M
Pa)
Experimental (MPa)
Filament-based simulation R²=0.87 Design-based simulation R²=0.46
Perfect matching
Heterogeneous strain field based on implementation of Filament-trajectory
Filament-based modelling: Best
fit to experimental
conditions
Conclusions
Relevant scale for FE modelling in additive manufacturing : microstructural heterogeneity
Conclusions Filament-based FE simulation: lack of cohesion
between filament + process-induced porosity
Conclusions Unrealistic predictions from CAD-based models
Conclusions Complex deformation mechanisms guided by
process conditions (printing angle)