Support Structures
Remedies
Reduce need for supports by reducing residual stresses as part is built,
(e.g. better process control, scanning strategies etc.)
More intelligent supporting algorithms to reduce unnecessary supports
Modify part design to require fewer supports
Modelling of SLM process
Thermo-mechanical FEA model
of SLM process taking into account
changes of state.
Interfaced with script that
provides input to model based
on process parameters.
Being used to investigate effect of
scanning strategies on residual
stress and microstructure
development.
Acknowledgment:
Luke Parry, PhD student
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Support Structures: Design rules for SLM
Vandenbroucke & Kruth (2007)
Sutcliffe et al. (2005)
Brooks et al. (2007)
Mercelis & Kruth (2006)
Thomas (2009)
Varying design guidelines
for different machines
Some angle limit
Horizontal overhang distance
Automated tool under development to
modify geometry to reduce support amount.
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Automated tool to modify geometry
Modify part design to require fewer supports as pre-build processing step
Multiobjective optimisation to find best build orientation that:
1.
2.
3.
Minimises modification required to geometry to self-support in regions
where geometry modifiers are to remain as part of the part
Minimises supports in regions where they will be removed
Minimises build height (build time)
Downward facing edges / faces
categorised based on violation
of self-support and
line-of-sight conditions
(tool access)
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Automated tool to modify geometry
Truss approach to geometry modifier, rather
than filling
+/- angled modifier geometry
Iterative generation of self-supporting
geometries
Act as pre-build geometry filter
Re-optimisation of geometry to compensate
for additional material
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Enclosed Voids
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Enclosed Voids
Draw direction constraint
Increase in mass of 17%
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Small minimum feature size
Efficient mesh improvement and analysis techniques
Example of octree decomposition with topology optimisation
Using high maximum element dimension and high adjacency rule
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Ongoing metal AM
design projects
ALSAM Project
Application: ALSAM (Aluminium Lattice Structures via AM)
Funded by the UK’s innovation agency, the Technology Strategy Board
With:
Develop and integrate technologies:
SLM of aluminium alloy
Lattice generation analysis and
optimisation methods
Efficient analysis and optimisation
techniques are required for lattice
structures which are highly complex
geometrically.
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ASID Project
Application: ASID (Advanced Structural Integrated Demonstrator)
Funded by the UK’s innovation agency, the Technology Strategy Board
(Highly Innovative Technology Enablers for Aerospace 2 (HITEA2) call)
With BAE Systems & Advanced Manufacturing Research Centre (AMRC), Sheffield
Develop & integrate technologies:
Thermoplastic composite structure.
Additive Manufacturing of topologically
optimised Titanium hinges.
Fastener-less joining of Titanium to
composite joints.
Assess potential to:
Improve current design philosophy
Reduce overall manufacturing cost and
life cycle maintenance requirements
Courtesy of
Need suitable design methods to allow application to practical
components to be built using SLM.
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INNOVATE Project
Application: INNOVATE (Integration of Novel Aircraft Technology)
Moving towards a More Electric Aircraft
Reduce fuel consumption: for high power-density electrical machinery.
Aim:
To show that the design freedom
offered by AM is the key for
the 3D optimisation of
machines
Objective:
Modelling and optimisation
of brushless electrical motors with
thermodynamics and electromechanics considerations
heat dissipation (novel heat-sink design)
electromechanical performance (novel rotor and stator designs)
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ALMER Project
Application: ALMER (Advanced Laser-additive-layer Manufacture
for Emissions Reduction)
Funded by the UK’s innovation agency, the Technology Strategy Board
(Highly Innovative Technology Enablers for Aerospace 2 (HITEA2) call)
With Rolls Royce, Materials Solutions, and The Manufacturing Technology Centre,
Coventry
Tackle manufacturing challenges so that
potential design opportunities afforded
by AM can be exploited fully.
Multi-disciplinary thermo-mechanical model
to predict residual stress during SLM build.
Investigate the use of lattice structures for
controlling residual stresses.
Integrate model into design & optimisation
tool to exploit the weight reduction
opportunities in component design and
minimise processing difficulties.
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Design for
Multifunctional
AM
Multifunctional 3D Printing
Centre Vision: To take AM beyond geometry and single materials to the
“printing” of multifunctional, multi-material components / devices /
systems in one operation.
Jetting process focused
Volume based geometric
modelling
Further design freedom and
complexity added to the
design process
Handling of interaction
between cost, mechanical,
electrical, thermal etc. to
determine overall optimal
solution
Complex modelling and
optimisation task
More info at:
www.nottingham.ac.uk/research/groups/3dprg
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www.3dp-research.com
Example Parts
Applied industrial part
Optimised Topology
Component placement (based on geometric
features and performance analysis)
Routing optimisation
(fixed and flexible order components)
3D routed
connections
Internal
component
placed and
oriented
More info at:
An optimization based design framework for
multifunctional 3D printing, (Brackett, Panesar,
Ashcroft, Wildman, Hague)
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Example Parts
Anthropomorphic arm
Representation with integrated sensors and conductive paths built using jetting.
Showpiece by summer intern students for Science
Museum exhibition: 3D Printing the Future.
Ongoing further work by final year
project undergraduate students
to optimise the design using
developed placement and
routing techniques.
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Summary
Need new design tools to maximise
potential of AM
Need to include the manufacturing
constraints of AM into tools
Lattices / Cellular structures
Topology optimisation
Tools to accommodate
manufacturing constraints
Simulation of manufacturing process
to allow better design
Tools for volume based design
(multi-material)
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Conference
Monday 7th - Friday 11th July, 2014
@ The Nottingham Belfry Hotel
Monday 7th July
(am) Introduction to AM & 3DP Master Class
(pm) Overview of research activities in UK Universities
Tuesday 8th & Wednesday 9th July
9th International Conference on AM & 3DP
Wednesday 9th & Thursday 10th July
ASTM F42 International Standards Group meeting
Thursday 10th & Friday 11th July
ISO/TC 261 Standards Meeting
More info at:
www.am-conference.com
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Dr. David Brackett
Faculty of Engineering, The University of Nottingham,
University Park, Nottingham, NG7 2RD, UK
Tel: +44 (0) 115 84 68441
Email: david.brackett@nottingham.ac.uk
Web: www.3dp-research.com
www.nottingham.ac.uk/3dprg