Automation ACTIVATE Dr Shanta Desai, CEng, CSci FIMMM Cytec Industrial Materials

A primary objective of the project is to high volume manufacturing

affordability of composite structures through;

a) Optimised cutting solution and slash implementation

b) Improve accuracy of component with cure distortion studies and tool optimisation

c) Automated angle / cross plying of multi layer formats

Project Overview of ACTIVATE- Affordable composites for high volume manufacturing of automotive structures

2 methods of cutting have been investigated;

1. Non-contact cutting using laser technology -University of Nottingham

2. Contact Cutting using Assyst Bullmer facility and equipment

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(a) OPTIMISED CUTTING AND SLASH IMPLEMENTATION

Nottingham University successfully conducted trials of cutting dry fabric,

prepreg and composites using laser technology. However challenges remain of

optimising to use it to implement slashes

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(a) OPTIMISED CUTTING AND SLASH IMPLEMENTATION

Trials with the support of Assyst Bullmer plant showed successful slash implementation via ‘contact cutting’

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(a) OPTIMISED CUTTING AND SLASH IMPLEMENTATION

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Limitations of current slash implementation

• Only a fixed slash pattern is achievable

• Cost due to high wear rate of roller die cutting knives. The wear rates

are significantly higher for certain slash angles e.g. 60˚

• Maximum die width 650mm hence, material width limitation

How do we overcome the above through ACTIVATE:

Localised slashes - Slash only where you need to!!

Low process cost, can be implemented by any cutting machine and no width

limitation.

(a) OPTIMISED CUTTING AND SLASH IMPLEMENTATION

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Punch

Die

Blank holder

University of Nottingham are working on generic component – Dust pan to generate a localised slash pattern

8 UD plies 0/45/90/-45/-45/90/45/0

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Localised slash pattern generation

Step 1: Insert cutouts where surface curvatures are high

Step 3: Determine minimum bounding area

Step 2: Surface flattening

Step 4: Generate slashes in the cut-off region in Step 2/

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Comparison of drapability of continuous, D-form and localised slashes material

Non-slashed

Localised slashes

D-form

Localised slashes on net shape

ACTIVATE Shear Angle– Model comparison

No slashes

Uniform slashes

Localised slashes

0º 45º 90º -45º

ACTIVATE Shear Angle– Model comparison

Stress concentrations of UD ply for double-dome geometry for (left) conventional UD ply (no slashes), (centre) a continuous slashed part (Dform) and (right) a localised slashed part.

Comparison in net shape

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(b) IMPROVE ACCURACY VIA CURE DISTORTION STUDIES AND

TOOL OPTIMISATION

• Formaplex have produced an aluminium trial

press tool with modular inserts to allow a range

of different material thicknesses to be pressed

• LMAT will carry out cure distortion studies on

flat and angled component sections made using

Cytec prepreg

• The outcomes of LMAT study will be applied to

optimise/compensate the tool surface to

achieve manufacture the final demonstration

component within geometric tolerances

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(b) IMPROVE ACCURACY VIA CURE DISTORTION STUDIES AND

TOOL OPTIMISATION

Current simulation considers thermo-elastic cool-down and chemical cure shrinkage only.

ACTIVATE Sample thickness= 2 mm, Max Deflection = .7mm Volumetric cure shrinkage was assumed to be 5% Max Deflection = 0.7mm

• LMAT FE solver expanded to include layered elements (20 noded brick & wedge)

• Phase transition model added to account for cure shrinkage in the rubbery state and thermal contraction in the glassy state

Main mirror

Reference mirror

Composite specimen

Wire clip

Location of the thermocouple

Laser pointers

Reflected laser beam

(c) AUTOMATED ANGLE / CROSS PLYING OF MULTI LAYER

FORMATS

ACTIVATE - Affordable composites for high volume manufacturing of automotive structures

Gudel UK have designed a pick and place end-effector for automated lamination Cytec will have a 2600mm wide cutting machine that will be supplied by Assyst Bullmer

Any questions?