Topology Optimization Requirements in the Age of Additive Manufacturing

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1 Topology Optimization Requirements in the Age of Additive Manufacturing Dr. Andreas Vlahinos Principal at Advanced Engineering Solutions Topology Optimization Roundtable Hilton Crystal City at Washington DC February 20, 2018

Current State Design Automation brakes down with current

trivial (Sub-D, Altair/Inspire, PTC/Freestyle, Dassault

Size optimization, morphing, post-processing High quality

Accurate mass properties Semantic GD&T Automated Assembly

definition for metrology (QIF) Technical Data Package

stl Validation step becomes easy (re-mesh skin and then

2 Current State Design Automation brakes down with current Topology Optimization tools CAD reconstruction is not trivial (Sub-D, Altair/Inspire, PTC/Freestyle, Dassault Systems 3DX, SANDIA) Why bother with CAD/NURBS? Size optimization, morphing, post-processing High quality mesh for validation step In the age of MBD/MBE we need: Accurate mass properties Semantic GD&T Automated Assembly Tolerance Analyses Inspection/Verification & process definition for metrology (QIF) Technical Data Package (TDP) for NASA & DOE projects Why bother with Facets/.stl Validation step becomes easy (re-mesh skin and then volume) File size matters (i.e. larger number lattice members) Cellular Lattice generation

3 Topology Optimization Output

4 CAD Reconstruction is not Trivial Sub-Divisional Surface Modeling with PTC/Freestyle

5 Sub-D models are great for: Geometry morphing, MBD and Meshing for Validation

Frame Lattice Generation Lightweight structural panels, energy absorption devices, thermal

Simpleware, Paramount Industries, NetFabb / Autodesk, PTC AM, 3DXpert Mature Topology Optimization

) to generate lattice structures We need smart lattice generation coupled to Topology optimization

6 Frame Lattice Generation Lightweight structural panels, energy absorption devices, thermal insulation, porous implants Infill / Conformal Lattices: ANSYS SpaceClaim, Materialise Magics, Simpleware, Paramount Industries, NetFabb / Autodesk, PTC AM, 3DXpert Mature Topology Optimization codes use element mesh (!) to generate lattice structures We need smart lattice generation coupled to Topology optimization Lattice element size based on the density field Node repositioning / rezoning base on density field Smooth transition between solid & lattice Consideration of Stress Concentration with homogenization

7 Smooth transition between solid & lattice based on the density field Requires strong geometry kernel

Useful Topology Optimization Features Manufacturing constraints Symmetry / pattern grouping / periodic patterns Minimum /Maximum Member Size Control Draw

Sheet metal Additive manufacturing (slopes for support-less elements) Multiphysics Structural, Thermal, Fluid, Electromagnetics Optimization Constraints

8 Useful Topology Optimization Features Manufacturing constraints Symmetry / pattern grouping / periodic patterns Minimum /Maximum Member Size Control Draw direction constraints for AM, extrusion, casting, stamping, radial filling, machining, etc. Sheet metal Additive manufacturing (slopes for support-less elements) Multiphysics Structural, Thermal, Fluid, Electromagnetics Optimization Constraints Stress, deflection, natural frequency, temperature Global and local buckling (lattice elements) Robustness evaluation Load magnitude uncertainties (μ, σ) Load Orientation uncertainties (μ, σ) Material properties uncertainties (μ, σ)

Infill with Minimal Surfaces Callophrys Rubi butterfly - Calcite particles Nature is a

are three fundamental minimal surfaces: P structures cosx+cosy+cosz=t (Primitive) D

(Gyroid) The unit cells of the P, D and G nodal surfaces (t=0) are periodic Great

9 Infill with Minimal Surfaces Callophrys Rubi butterfly - Calcite particles Nature is a great designer Minimal surfaces unlock Natures maximum structural efficiencies There are three fundamental minimal surfaces: P structures cosx+cosy+cosz=t (Primitive) D surface coszsin(x+y)+sinzcos(x-y)=t (Diamond) G surface sinxcosy+sinycosz+cosxsinz=t (Gyroid) The unit cells of the P, D and G nodal surfaces (t=0) are periodic Great infill structure It doesn t need supports Great compression strength Heat exchanger capability

10 Thickness of Minimal Surfaces based on the density field Primitive Schwarz P Faceted Lattice Diamond Schwarz D Faceted Lattice Gyroid Gyroid Faceted Lattice

Design Optimization is more than Topology Topology Optimization Finds best

variables are dimensions of any elements properties like beam section, shells

Shape Optimization Finds the best possible shape.

and shape of bead patterns to stiffen panel structures.

11 Design Optimization is more than Topology Topology Optimization Finds best distribution of material for stiffness or compliance Sizing Optimization Design variables are dimensions of any elements properties like beam section, shells thickness and composites orientation etc. Shape Optimization Finds the best possible shape. DV are perturbation vectors on FE domains Topography Optimization - Find the location and shape of bead patterns to stiffen panel structures. Nodes move normal to shells Topometry Optimization DV are all element properties i.e. all lattice structure sections Freeform Optimization Finds the best location and shape of rib patterns that stiffen solid structures

12 Early Adaptors used TO & ALM in Critical Components Jan 6, 2014, SpaceX launched its Falcon 9 rocket with a 3D-printed Main Oxidizer Valve (MOV) body Monday, March 12, Automotive Simulation World Congress 12

Synthesis of Metamaterials using Topology Optimization & Lattices Metamaterial is a synthetic composite material with a structure

level and build it with multi-material metal 3D printers Examples of mechanical metamaterials Materials with negative Poisson's

Pentamode metamaterials or meta-fluids that have finite bulk but vanishing shear modulus Material with zero coefficient of thermal

13 Synthesis of Metamaterials using Topology Optimization & Lattices Metamaterial is a synthetic composite material with a structure such that it exhibits properties not usually found in natural materials Sometimes we need to design the structure at a microscopic level and build it with multi-material metal 3D printers Examples of mechanical metamaterials Materials with negative Poisson's ratio (auxetics) Defense applications Material with negative stiffness, longitudinal and volume compressibility transitions Pentamode metamaterials or meta-fluids that have finite bulk but vanishing shear modulus Material with zero coefficient of thermal expansion Acoustic or phononic metamaterials can exhibit acoustic properties not found in nature, such as negative effective bulk modulus

Fundamental Challenge Characterization of Additive Manufacturing Materials Geometry / FEM CAD Part with PMI Lattice Structure Support Structure FEM Mesh Physics definitions Processes Settings Laser

thickness Disposition path Build orientation Print Preview Multi Physics Simulation for Characterization of Additive Manufacturing Materials What material properties should I use in TO?

14 Fundamental Challenge Characterization of Additive Manufacturing Materials Geometry / FEM CAD Part with PMI Lattice Structure Support Structure FEM Mesh Physics definitions Processes Settings Laser power Pulse rate Spot size Velocity Spacing Material Selection Alloy composition Powder diameter Powder compaction Service active trace elements 3D Printer Control Software Printability Checks Layer thickness Disposition path Build orientation Print Preview Multi Physics Simulation for Characterization of Additive Manufacturing Materials What material properties should I use in TO? Material Performance Field Modulus of elasticity Ex(x,y,z) Poisson s ratio Coefficient of thermal expansion Density Yield strength Ultimate strength Fatigue strength Residual stress distribution Distortion of the part Damping Thermal conductivity etc.

Nouveautés ANSYS pour le calcul structurel et l impression 3D. CADFEM 2017 ANSYS Additive Manufacturing

Titelmasterformat Journée Technologique durch AddiPole Klicken bearbeiten Nouveautés ANSYS pour le calcul structurel et l impression 3D Titelmasterformat Structural design with durch ANSYS Klicken bearbeiten