Thermally-actuated composite helical lattices: prediction and - - PowerPoint PPT Presentation

Thermally-actuated composite helical lattices: prediction and validation

Jonathan P. Stacey, Mark Schenk, Carwyn Ward, Matthew P. O’Donnell CDT Conference 16th April 2019

Presentation Outline

CDT Conference – 16th April 2019 JP Stacey, M Schenk, C Ward, MP O’Donnell

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• Introduction
• Methods
• Results
• Conclusions

Introduction

CDT Conference – 16th April 2019 JP Stacey, M Schenk, C Ward, MP O’Donnell

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• Composites offer unique

stiffness tailoring routes

• Rich design space available
• Thermal response of non-

symmetric laminate causes curvature changes

• Extreme mechanical

behaviour possible

Methods

CDT Conference – 16th April 2019 JP Stacey, M Schenk, C Ward, MP O’Donnell

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Analytical

• Optimise fibre angles

Finite Element Analysis (Abaqus)

• Shell models, quasi-static
• Parameter sensitivities: length, width, joint

type, friction, prestress

Experimental

• Temperature-Extension
• Force-Extension

+ HEAT

Results

CDT Conference – 16th April 2019 JP Stacey, M Schenk, C Ward, MP O’Donnell

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• Good match between FE

and experiment

• Achieved extreme negative

CTE (-3285·10-6 K-1)

• Beam vs Shell models
• Joint friction and end

effects less significant

Conclusions Future Work

CDT Conference – 16th April 2019 JP Stacey, M Schenk, C Ward, MP O’Donnell

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• Working prototype composite

helical lattice structure

• Extreme behaviour can be

designed and realised

• Good correlation between

experiments and FE analysis

• Some key parameter

sensitivities investigated

• Explore dynamic snapping

behaviour

• Improve manufacturing

robustness

Thank You

jonathan.stacey@bristol.ac.uk