ulster.ac.uk

Textiles and Multi-axial ReinforcementsDr Alistair McIlhagger

Contents

• Technical Textiles• Textiles/Composites in NI• ECRE• Principle Areas• Ulster Research• Historical Importance in NI• The Technology of Weaving• Benefits of 3D• Challenges• NIACE• Competence Centre Projects• Sensing

Technical Textiles

• Coined in the 1980s to describe the growing variety of products and manufacturing techniques being developed primarily for their technical properties and performance rather than their appearance or other aesthetic characteristics - superseded an earlier term 'industrial textiles' which had become too restrictive in its meaning to describe the full complexity and richness of this fast growing area.

Source -https://connect.innovateuk.org/web/technical-textiles

Textiles/Composites in NI

• Mackies, Courtaulds, Langford etc

World Class Examples

Engineering Composites Research Centre

Background Information• Faculty of Engineering – ERI – ECRE and AmFor –

Firesert, Centre for Sustainable Technologies, Art and Design Research Institute etc

• ECRE approx 35 years textiles/composites• Bombardier Transformation Programme• Course provision and development • Royal Academy Bombardier Professorial Chair

Principle Areas

Principal areas

• Advanced design, manufacture and analysis of preform composite structures

• Advanced machine development for preform manufacture

• Development of “bespoke” advanced materials solutions

• Skills development and training

• Grant applications and funding – national/international

• Access to unique manufacturing and testing facilities

• Project management and financial development

• Certification and standards implementation

• Application of novel fibre and resin systems

• Development of cost/life cycle modelling including recycling/reuse issues

Ulster Research

Ulster Research

Ulster Research Microvascular

Ulster Research Microvascular (contd)

Waste Materials

Historical Importance in NI

Most Famous Image in the Early History of Computing

Portrait woven in silk on a Jacquard loom and required 24,000 punched cards to create (1839). Charles Babbage - inspired him in using perforated cards in his analytical engine.

Historical

Early aircraft used woven clothcovering. It was sewn overa covering of wooden and/orsteel tube frames and formers

Early commercial aircraft hadwoven cloth covering the wingsand aft body. The cloth was stiffened and filled (to preventair leakage) with cellulose dope

Market Information

The growth of composites (as a high strength to weight ratio material) is follows:

Update 2014 report

• Total Predicted Market Size for Carbon Fibre all Industries $13.6bn (2010)

• Aerospace Predicted market size (40%) $5.5 bn (2010)

• The Aerospace market is predicted to increase to 90% by 2025

• The market for 3D Woven Carbon Fibre Preforms is in very early stages

• The potential market for 3 D woven Carbon fibre composites is estimated to be in excess of £100 million pa. Globally across the aviation industry (aerospace structural and engine components)

• The major carbon fibre manufacturers have increased their raw materials production to 21,000 tonnes pa with a forecast value for 2010 of $13.6 bn

• The growth in carbon fibre across all sectors is predicted to exceed 110000 tonnes pa by 2018 with aviation exceeding 16,000 metric tonnes with an estimated value of $1.27bn

The Technology

3D weaving places selected fibres in the z or out-of-plane direction.

This z direction has been, and still is the Achilles' heel for composites.

Basic Weaving

Comparison

Table: Common methods of preform production (Bannister, 2004)

Advantages of 3D Wovens

Textiles in composites revealed two sets of benefits:

• Delamination resistance- Primarily derived from through thickness orientation of yarns

• Potential for reduced cost- Pre-assembled layers of fibers reduce touch labor- Part consolidation can be realized with near-net-shape manufacturing

Common 3D Weaves

Layer-to-layer Through thickness

Review of Literature Difficult?

- Comparing “like with like”

Weaving at Ulster

leg prosthesis

The Beginning

To the Present

The Opportunity

The Benefits

The impact energy needed to initiate damage in 3D woven carbon composites is up to 60% higher than in a 2D carbon laminate.

3D woven materials are insensitive or at least have very low notch sensitivity.

Impact performance observed using CT

Open hole tension tests with strain field map for a) 6% layer to layer and b) 6% orthogonal structures

The Benefits

Better fatigue properties than the corresponding 2D composite (15% better at 105 cycle at applied stress level of 75% ultimate strength).

Mode I interlaminar fracture toughness up to 20 times higher than the unidirectional carbon fibre reinforced epoxy laminates.

Representation of a DCB test

Image of a layer to layer DCB specimen under load

The fracture surface of a layer-to-layer specimen. Sites where 3D reinforcement was broken are circled

The Component Level

Fabric Designs and Concepts

Some Difficulties

Developments

Other Developments

Use of Advanced Preforms

Weaving

Challenges

Crimp in textiles– Crimp levels influence fiber volume fraction, thickness of fabric, and mechanical performance

of fabric. – High crimp leads to– Reduced tensile and compressive properties– Increased shear modulus in the dry fabric and the resulting composite– Fewer regions for localized delamination between individual yarns.

Development of New Machinery/Processes– Very complex shaped objects can be produced with textile processes– New processes or machinery are required.– Particular emphasis is on placement of bias yarns in woven fabrics

Variation in Weave Design– Formation of a tapered fabric– Weaves have gradients in a single or double axis by changing yarn size in the width or length– Complex shapes can be achieved through “floating” and cutting yarns to reduce total number

of yarns in some section of the part

More Challenges

Advanced Weaving

Physical Limitations within Literature • Current cost of production.

– modifications to machines are needed for shaping capabilities, – capital cost is applied to a few prototypes, the unit cost is tremendous

(no economy of scale)• Processing difficulties.

– infiltration at high pressure, and thermal effects during curing. • frequently results in internal yarn geometry distortions. • elastic and strength properties have high variation.

– thermal effects can result in local disbonds from yarns

Failure Analysis within Literature

NIACE

• NIACE• NISP• Funding Bodies • Academic Institutions• FE Colleges – SERC, BMC• International appeal

Benefits to/from NIACE

•Provides route for reduced development time – roadmap for continuous

development from “blue” sky to full product/commercialisation

•Skills of both universities and companies provides a unique and differentiated

approach to advanced materials usage from concept through to

implementation and full modelling/life analysis

•Shared responsibility for undertaking projects – financial and risk orientated –

ideas/expertise provided by others should also enable new perspectives and

solutions for company

•Potential increased access to funding (and success in applications) –

opportunities to engage in projects with academia and other companies

Benefits to/from NIACE (contd)

•Partnerships with QUB/UU, other companies depending on specific

projects and the interaction of the centre will have on

national/international stage

•Access to cross-border funding and collaboratively with IComp and

its members – Fusion/KTP

•Access to equipment for manufacture and testing.

• “Try out” without purchase of expensive equipment

•Placement of employees within centre – rather than just product

delivery

•Access to different aspects of engineering – manufacturers,

designers etc

Benefits to/from NIACE (contd)

•Place/fund employees students within other organisation/university

concentrating on specific skills

•Physical nature of co-location extremely powerful “vehicle” for

sharing of ideas and skills – provision of seminars to “educate”

•Universities will still be involved in their research and progression

through TRL levels

•A place to bring others !!!!

Competence Centre Projects

• Reusable Bagging• High load joints• Repair• Recycling• etc

Sensing

• Light weight, high-speed, and self-powered wireless fibre optic sensor (WiFOS) structural health monitor system for avionics and aerospace environments

• “Tailored” sensing configurations• Key elements

• System - Collection/Data/”properties”• Powering• Cost• Wireless

Challenges

Weaving Technical Challenges