1

An Introduction to Aerospace Composite

Manufacturing Technology

Greg Hasko

Applications Engineer

Connecticut Center for Advanced Technology

ghasko@ccat.us

2

Aerospace Composite Manufacturing Assessment

Introduction

This document is intended to be an introduction to the various

processes used in manufacturing structural composites for

aerospace. We review the raw materials, primary and secondary

manufacturing methods, inspection, emerging methods, and

software tools that enhance the flow of information between

design, analysis and manufacturing. Links are provided to the

sources in each of the topics covered. This document will be

updated on at least an annual basis.

3

page

Part Characteristics – Airframe vs Engine 4

Raw Materials – Fibers, Matrices, Inserts 6

Manufacturing Methods – Shaping and Curing 11

Material Formats 19

Processes & Equipment 25

Emerging Methods 63

Software Tools – Design, Analysis, Manufacturing 71

National Resource Centers 83

Contents

4

Typical Airframe Part Characteristics

• Large dimensions; several feet to 10‟s of feet.

• Low to medium contour.

• Mostly moderate temperature environment.

• Need damage tolerance.

• Some need anti-ice.

• Mostly one part / per part-number / per vehicle.

5

Typical Engine Part Characteristics

• Smaller dimensions; several inches up to

several feet.

• More severe contours.

• Temperatures can go beyond polymer matrix

capability.

• Need damage tolerance, erosion resistance.

• Some need anti-ice.

• Can have multiple parts / per part-number /

per engine.

6

Composite Structures are Created by

Combining the following Materials

• Fibers

• Matrix

• Cores and Inserts

• Adhesives

7

Density

[Lb/in3]

max use

temp [F]

modulus

[MLb/in2]

strength

[KLb/in2]

CTE

[x10-6 in/in/F]

Fiberglass [two types] .091 700 10-13 500-650 3

Aramid [multiple brands] .052 500 17 400 -3.5

Graphite [many types] .063 1000 33/43/64+ 300-800+ -.05

Silicon Carbide .090 2400 28 400 2

Fiber Materials

• Aerospace parts are made from a few types of fibers.

• They vary widely in density, mechanical properties and cost.

• If not planned carefully, fiber deposition can add high labor costs.

• The thermal expansion needs to be accounted for in tool design.

8

Density

[Lb/in3]

max use

temp [F]

modulus

[MLb/in2]

strength

[KLb/in2]

CTE

[x10-6 in/in/F]

Epoxy .046 200 0.5 10 40

Bismaleimide [BMI] .046 300 0.7 15 40

Polyimide .052 500+ 0.5 10 25

Polyethersulfone

[PES]

.049 350 .4 12 27

Polyetherether-ketone

[PEEK]

.048 250 0.5 15 25

Carbon .063 3000+ 1-2 1 1-2

Ceramic .090 2000+ 10 10 2

Metal .10-.16 1000+ 10-17 20-100 5-12

Matrix Materials

• Aerospace parts are made with several types of matrix materials.

• They vary widely in temperature resistance, processing

characteristics and cost.

9

Density

[Lb/ft3]

max use temp

[F]

Fiberglass/phenolic honeycomb 3-8 500

Aramid/phenolic honeycomb 2-9 350

Foam, closed cell, PMA 2-19 300

Syntactics

[glass spheres in resin matrix]

40 200-450

Solid Laminated or Metallic Core Inserts 95-173 200-600

Inserts

Metallic fasteners with special features for strong

joints in composites, typically bonded in place.

Functional Materials Various materials are being embedded to enable

structural health monitoring and actuation.

Cores & Inserts

• Aerospace parts are frequently made in a sandwich construction of

composite skins with low density cores.

• Local inserts are used for strength at joints.

10

Form Characteristics

Paste Usually a 2-part system that is mixed just prior to application.

Some cure at room temperature, some at elevated temperature.

Film Thin films supplied on rolls, and must be refrigerated. They can be

cut and applied in selected patterns. They require heat to cure.

Foaming These are pastes that foam upon cure, to fill hollows in a part or to

splice edges of honeycomb cores.

Powder Tackifier Usually a version of the matrix resin that is applied to dry fabric

used for RTM parts. The powder is used to provide tack to hold

plies together during preforming steps. It should not detract from

the cured mechanical properties.

Nano Additives A wide variety of materials and forms take advantage of the unique

properties at the nanometer level. Order-of-magnitude increases

are possible in mechanical and electrical properties of matrix

resins, adhesives and coatings.

Adhesives

There is a wide variety of adhesives used in aerospace

structures, available in several compositions and forms.

11

Composite Manufacturing

Methods

12

Manufacturing Methods

There are two main approaches for manufacturing of composites, based on

whether the resin is introduced before or after shaping the fibers.

• Choices made in the design of a part influence which branch is

followed, and the types of processes and equipment that are used.

• Cost-effective parts need to be designed with a knowledge of the

processes involved.

• Repeatable quality and cost are achieved by properly specifying all

parameters.

FIBER

RESIN

CURE

RESIN SHAPING

SHAPING

13

Manufacturing Methods

Another way to classify manufacturing processes is by the shaping

and the curing methods.

Curing - Heat & Presure

• Self-Contained Mold

• Press

• Autoclave/Vacuum Bag

• Oven/Vacuum Bag

• Electron Beam/Vacuum Bag

• Pultrusion

Shaping

Fabric, Manual

• Prepreg or, w/ Tackifier

• Stitching

Machine

• Filament Wind

• Braid

• 3D Weave

• Pultrude

• Stitching + fixtures

• Automated Fiber Placement

14

Resin Applied Prior To Shaping [Prepreg Material]

DRY FIBER TOW

RESIN

2D WEAVE

AUTOMATED

FIBER

PLACEMENT

AUTOCLAVE

MOLD

COMPRESSION

MOLD

RESIN

AUTOCLAVE

MOLD

CUT

FILAMENT WIND

LAYUP

PULTRUDE RESIN

ROLL WRAP

The typical sequence for these types of processes:

15

Resin Applied After Shaping [Dry Material]

DRY FIBER

2D WEAVE/BRAID*

3D WEAVE/BRAID*

RESIN

TRANSFER

MOLD*

OVEN,

PRESS CUT

RESIN

*There are many variations of these processes

PULTRUDE

RESIN

FILAMENT WIND/

BRAID OVEN

RESIN

PREFORM

The typical sequence for these types of processes:

16

Design / Manufacturing Information Flow

Information flow is as important as material flow.

Bill of Materials

Sequence of Operations

Ply s/n

Ply orientation

Drawing

Cutting File

3D CAD Model

Ply shapes & s/n‟s

Machine-specific

software for cutting plies

Company-wide

software for

purchasing and

scheduling

Documentation for

technicians

Structural FEA Model

Process FEA Models

[emerging]

Process Specifications

17

Finished Part Manufacturing Methods

Method Guidelines Airframe Engine

Manual Layup / Resin

Transfer Mold

•All surfaces are tooled

•Good for multi-hollow parts

X X

Manual Lauyp / Compression

Mold

•All surfaces are tooled

•Practical size limited by press capacity

X

Manual Layup/Autoclave Mold •Usually one surface is tooled, but can

add caul sheet on opposite side

•High capital and operating costs

X X

Automated Fiber Placement/

Autoclave Mold

•High deposition rates

•Allows continuous fibers over large areas

X

Filament Winding, Braiding •Variable cross section

•Minimal labor

X

Roll Wrapping •High Rate

•Circular sections, tapered

X

Pultrusion •High rate, constant cross section

•Minimal labor

X

Machining •Need special bits, settings, coolant

•Can use ultrasonic, laser and waterjet

X X

18

1. Tooling – to deliver an accurate shape after cure.

2. Accurate fiber placement – alignment within 2° of nominal, uniform

spacing, no wrinkles.

3. Complete resin introduction – no dry spots, typically 40 – 50% by volume.

4. Air removal – minimal void content, below 2%.

5. Compaction – for good strength-to-weight ratio, need from 14 to 150 psi.

6. Cure – needs to be above the maximum service temperature.

7. Finishing operations: machining, bonding, coating.

Common Needs for All Manufacturing Approaches

19

Material Formats

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Typical Characteristics of Prepreg Materials

Resins are applied to single tows that are up to ¼” wide, or to 2D fabrics,

that are stored on spools. This process, called prepregging, adds cost but

eliminates the need for the part fabricator to worry about resin mixing and

resin content.

The physics of resin flow into fibers limit the ply thickness that can be

made to the range of .005 to .050”. The primary type of resin used in

aerospace is thermosetting, has a limited working time at room

temperature, and must be stored under refrigeration. Thermoset prepregs

are tacky, which aids laying up plies into contoured molds. Thermoplastic

prepregs do not need refrigeration, and are not tacky.

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Typical Characteristics of Dry Fiber Materials

Dry processing uses the lowest cost form of the raw materials. Resin is

introduced by the Resin Transfer Molding [RTM] process, or by in-line

wetout. The thickness that can be molded is only limited by the resin

characteristics; the flow time before it gels and the threat of exotherm in

thick areas. Some resins give off gaseous byproducts that need to be

removed before cure. Dry fibers are not tacky, and require binder

materials or stitching to stabilize complex shapes. Some binders are

thermosetting and dissolve into the matrix resin.

22

Typical Characteristics of Conventional Fabrics

• Many types; plain, satin, crowfoot, etc.

• Widths can be up to 5‟.

• Large databases of material properties exist.

• The size and type of fiber in each direction can

be varied to create hybrids. An extreme case is

“uniweave”, with heavy graphite in one direction

and fine fiberglass in the other, to approximate

prepreg tape.

23

Typical Characteristics of Non-Crimp Fabrics

• One ply can have multiple layers at different angles, held together by

lightweight knitted fiber; can reduce labor content.

• Cured laminates have higher properties than conventional weaves.

• Widths can be up to 12‟.

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To improve impact, strength and thermal properties in the

thickness direction, a variety of methods are available:

• 3D Weaving & Braiding – Jacquard looms, etc

• Stitching – industrial strength

• Z Pins – small embedded composite pins

3D weaving and braiding also reduce ply layup labor;

however the linear production rate is slower than 2D fabrics.

Methods to Increase Through-Thickness Properties

25

Manufacturing Processes

and Equipment

26

This is the traditional method, needing trained

technicians. It can be done with prepreg and dry

material. To form the material around tight

contours without wrinkling, relief slits or „darts‟ are

cut. Fibers within a ply shear and skew as they

are placed onto contoured molds. The pattern of

darts and the sequence of laying down the

perimeter of large plies needs to be repeated from

part to part.

This method is susceptible to FOD being cured

within the laminate; gloves, tape, knife blades, etc.

Hand Layup

27

Ply Placement Templates and Draping

For repeatability when using hand layup, guides

are needed to align ply directions and edges.

These guides can be scribe lines on molds, mylar

sheets, or fabricated metal or composite templates

that pin into location at the edge of the mold.

Plies at the edge of a part may have extra tabs

designed into the flat patterns to allow verification

by an inspector. These tabs are trimmed off after

cure.

Note that the weave pattern distorts when placed

onto a contoured mold. The hoop strength of the

red zone is much different than the blue zone. The

designer must specify the draping method, and this

information must be transmitted to the shop floor.

See the Software section for packages that can

simulate draping. +/-30° 0/90°

28 Video-Guided Ply Placement

Laser-Guided Ply Placement

CAD-Driven Ply Placement Guides

Projectors that operate from CAD data

display ply patterns and fiber angles onto

the mold during hand layup. Line width

adjustment is needed in highly sloped

areas. Tolerance bands can be indicated

in the projected pattern.

29

These machines are used for dry or

prepreg material. Ply shapes are

determined manually and scanned into

a digital data file, or determined from

software that models draping and

flattening for contoured shapes.

Software is also used to pack the ply

patterns efficiently to minimize waste

when cutting.

CNC Ply Cutter

30

Modified „shoelace‟ machines are used, usually with dry fibers.

Braided sleeving can be packaged on a spool for hand layup,

or contoured mandrels can be fed through the machine to

braid onto the net shape. Braided preforms typically go into an

RTM process, although prepreg and in-line wetout have been

demonstrated.

Large commercial braiders have an approximate 7-foot ID,

which can be fully covered with near-hoopwise fibers.

However, another limit is the diameter that can be fully

covered at a given angle with the fiber bandwidth of about

.25”. The maximum diameter that can be fully covered at a 45

degree angle is 8”. Specialty braiders exist that are almost

four times this size.

Since all the spools on the machine must pass over and under

each other, they are smaller than those on weaving looms.

Therefore, reloading time is a factor in determining the

maximum attainable length and cost. Typical parts include

propeller spars, missile bodies, bushings, accessory beams.

Braiding Processes

31

Braiding machines can be set up to deliver one or two sets of fiber; a biaxial set and an

axial [0 degree] set. The combination of biaxial and axial is called triaxial. The angle

of the biaxial fibers can range from nearly 0 degrees to nearly 90 degrees. Different

types and weights of fiber can be used to create hybrids. The choices of these

parameters depend on the structural and cost requirements.

Straight and curved parts can be made by using appropriate mandrel handling devices.

The cross-section can not have concave areas, or the fibers will bridge. Severe cross

section changes can be accommodated, such as the transition from the cylinder to the

flange of a bushing. The mandrel can be reciprocated back and forth to build up

layers. Other fabrics and core materials can be inserted between layers. Removable

pins on the mandrel enable net-shaped holes without drilling.

Braiding Parameters

0 0

Biaxial Triaxial

32

3D fiber architectures and shaped cross-

sections [I, T, hollow, etc] are made on

braiders that control the motion of every

fiber spool. Jacquard weaving looms

control the interweaving of each yarn to

achieve similar results.

3D Braiding and Weaving

3Tex I-Beam

3D Braider

Jacquard Loom

Individual yarn

controller

33

Dry fibers are pulled through a resin applicator

and a curing die. Shaping and curing occur nearly

simultaneously. Typical parts are floor beams and

strengthening inserts in wing spars. Entire wing

sections have been demonstrated.

Parts are limited to straight, constant cross-

sectional shapes. Parts to several feet in width

can be pultruded, given enough pulling capacity.

Length is limited only by the creel capacity and

take-up provisions. Fabrics, cores and inserts can

be incorporated.

A variation called Pullforming is used in the

automotive industry to make leaf springs. Wet

fibers are drawn onto a heated rotating mandrel

having a shaped cavity.

Pultrusion Process

34

Resin Transfer Molding Processes

In this process dry preforms are enclosed in a mold, then a thermosetting

resin is introduced. This reduces capital and operating expenses

compared to autoclave curing. Very complex parts can be made, such as

vane/ring packs. Resin selection is limited to those that have low

viscosity [<1000 cP], for long enough time [typically 1 hour] to complete

the injection. There are numerous variations, basically divided into

matched mold and bag mold methods. There are some similarities to

plastic injection molding, but the resin is much lower in viscosity and the

cure cycle is much longer than a quick cooling cycle. Part quality is

improved with dry nitrogen purging followed by vacuum.

RTM Transmission Fitting

• Thick-wall graphite composite.

• ~20-piece mold was used.

• Final edges were machined.

35

Preforming for RTM Processes

A binder is applied to the fabric before plies are cut out. Plies are

shaped and stabilized on preforming molds, usually with vacuum and

some heat, prior to assembly into the RTM mold. This increases

preform repeatability and reduces the RTM mold cycle time.

Stitching is also used to make shaped preforms, and in addition provides

translaminar strength. Fixtures hold the fabric in alignment during the

stitching process.

36

RTM in a Matched Mold

RTM Mold

Injector or pressure pot

Vacuum Pump

RTM in a matched mold provides an excellent finish on all surfaces. It

enables using 3D textile preforms that can not be made by prepreg

methods. Parts are typically up to a few feet in size.

The preform has a great influence on the flow pattern. The closed mold

is a pressure vessel [typically 100 to 200 psi], and needs great stiffness

to yield parts with uniform wall thickness.

37

Typical Features of RTM Molds

• Inlet and outlet ports – locations optimized to completely fill the preform.

• High stiffness to resist preform compaction and resin injection pressures.

• Clamps - either around the perimeter, or use an external frame or press.

• Heating – can be integrally heated with electric rods, steam, or hot oil, or a press or oven can be used.

• Sensors – thermocouples and other types to monitor pressure and degree of cure.

• Vacuum-tight; O-rings enclose the part cavity.

• The mold can have multiple cavities.

• Molds may have over 100 internal pieces, manually assembled.

• Trapped mandrels are removed using melt-out or wash-out materials.

38

This is done on a one-sided mold, with a vacuum

bag on other side. Resin is drawn into the

preform with vacuum. A high-flow media can be

placed over the preform so that resin quickly

spans large parts. The bagged side has a

rougher surface than the mold side after cure.

Mechanical properties are typically lower than

with an autoclave pressure cure or with matched

mold RTM. Parts can be up to 10‟s of feet in size.

Vacuum Assisted Resin Infusion [VARI] Process

39

Resin Film Infusion [RFI] Process

This is a variation of VARI, using a one-sided mold and a vacuum bag on

other side. A solid resin film is placed on the mold, then covered with the

preform and a vacuum bag. As this assembly is heated, the resin melts and

flows into the preform under vacuum pressure. This process can also be

done in an autoclave for additional compaction and driving pressure.

As with prepreg and VARI, the bagged side has a rougher surface than the

mold side after cure. Parts can be to 10‟s of feet in size.

Can have very thick preforms

Solid resin film

Resin melts

and flows

Mold

Vacuum bag

40

For VARI processing an open container will

suffice, since resin is drawn in with a

vacuum pump. For injection into a matched

mold, a pressurized paint pot can be used.

Positive displacement pumps enable

computerized process control and recording.

Meter-mix machines can be used with dual

component resins.

Most resins need to be heated to reduce

viscosity, so heated chambers and delivery

hoses are available.

RTM Injection Equipment

41

Prepreg materials can be cured in a matched mold

as in RTM, giving good surface finish throughout

[as opposed to bag methods such as autoclave or

VARI].

Maximum size is governed by press capacity,

typically up to several feet. Vacuum is typically not

needed. Proper sequencing of pressure during the

heat cycle is critical to making void-free parts with

proper fiber alignment. Typical parts are stator

vanes.

Compression Molding Processes

42

This uses a device similar to a lathe. A revolving mandrel is

covered with fibers kept under tension. It can be done using in-

line wetout, prepreg, or dry fiber followed by an RTM cure.

Curing is normally in an oven. External cauls or shrink wrap

film can be used for compaction. Typical parts are pressure

tanks and rocket bodies.

Since fibers are kept under tension, the cross-section can not

have concave areas or the fibers will bridge. They must either

lay down in geodesic patterns normal to the local contour, or

extra mechanical means such as pins or friction must be used

to prevent slipping. These factors must be observed in the

design phase. The fiber angle can range from 0 [with

appropriate restraints at the ends] to 90 degrees to the rotation

axis. Large spools of fiber can be used, as in weaving.

Shapes are limited to the number of controlled axes of the

machine; slightly tapered straight parts such as truss tubes can

be made on a 2-axis machine, whereas curved parts with

closed ends may require 5 axes. Length and diameter can

range up to 10‟s of feet. Parts have been made over 100‟ long

with over 1” wall thickness.

Filament Winding Processes

43

Automated Fiber Placement [AFP] takes filament winding

a step further. It uses prepreg fibers placed onto a

contoured mold with a multi-axis head. Fibers are

stabilized by the resin tackiness and contact rollers. Labor

content is reduced and speed increases compared to hand

layup. Typical parts are fuselage and nacelle skins.

The size can be 10‟s of feet on a side. Both the mold and

the fiber placement head are in motion. Individual fibers

can be cut and restarted to cover any shape at any angle.

As opposed to filament winding, concave features are

permissible.

Parts are vacuum bagged and cured in an autoclave.

See videos:

http://www.automateddynamics.com/video_library.php

Automated Fiber Placement Processes

44

Special machines have been developed

to deposit prepreg fabric. They can lay

fabric on a mold and trim the edge. They

are used for mildly contoured shapes

such as wing skins.

A variation is to use a “pick and place”

robot to stack pre-cut plies on a mold.

Robotic Ply Layup

Broetje pick and place robot

45

Prepreg is rolled onto a mandrel and

cured in an autoclave, or shrink wrapped

for an oven cure. Mandrels must be

straight and circular, but can be tapered

or stepped. Tables typically are

designed for parts up to 10‟ length and

up to 6” diameter. Typical parts are truss

tubes.

Tube Rolling Table

46

Heated pressure vessels are normally

used to cure prepreg materials. They

can be 10‟s of feet in diameter and

length. One-sided molds are

normally used, and several parts that

have the same resin can be cured

together. Resin Film Infusion into dry

preforms has been demonstrated on

large parts having translaminar

reinforcement.

Autoclaves

47

Used for compression molding

and RTM. Heat is supplied by

electric cal rods or an oil system.

Presses typically have one axis of

motion for slightly contoured

parts, but custom presses have

been built with multiple axes.

Heated Press

48

Ovens can be 10‟s of feet in length,

width and height. They may have a

rotisserie for filament wound parts, to

avoid resin pooling. They are used

for heating bolted RTM molds or

vacuum-bagged VARI molds.

Heating can be electric, gas or oil.

The floors may need to withstand

multi-ton molds.

Ovens

49

Inspection Methods, In-Process and Post-Cure

This is a dynamic, rapidly evolving area that entails a variety of physical

principles. In-process checks are done to verify proper ply sequence, ply

angle, and ply edge location. Post-cure inspections check for non-desirable

items such as wrinkles, voids, delaminations, and embedded foreign objects.

In some methods the structure is passive, with defects creating a disturbance

to an applied signal. In others the structure is mildly disturbed with heat or a

mechanical load, and the surface is scanned for indications that print through.

Acousticam Sonatest Wheelprobe

50

The tool bits, feeds, speeds and coolants

used to machine composites are specific

to the matrix and fiber combination.

Excessive heating causes polymeric

resins to decompose. Improper cutting

tools can pull fibers out of the resin

locally. Lasers and waterjets are used,

especially on ceramic matrix composites

where the part is made out of similar

materials as the cutting tools themselves.

Residual stresses locked into the part

during cure can cause parts to deform or

delaminate during machining.

Machining

Trim & Drill Fixture

51

Custom-designed fixtures are used to hold

parts accurately and maintain bondline

thickness despite thermal expansion

effects. They can be self-heated or used

in an oven. For quality control they are

instrumented with thermocouples.

Bonding Fixture

52

Composite Manufacturing

Related Companies

53

Method Company Web site

Manual Layup /

RTM

V Systems

ITT Integrated Structures [ex Fiber Innovations]

AAR Composites

Albany Engineered Composites

GKN-CT/AL/St Louis

Cobham [ex Sparta]

North Coast

www.vsc-inc.com

www.defense.itt.com

www.aarcorp.com/composites

www.albint.com/aec

www.gknaerospace.com

www.composites.sparta.com

www.northcoastcomposites.com

Manual Lauyp /

Compression

Mold

GKN-CT/AL/St Louis

CTL Aerospace

CHI

Matrix

Cobham [ex Sparta]

www.gknaerospace.com

www.ctlaerospace.com

www.chi-covina.com

www.matrixcorp.com

www.composites.sparta.com

Finished Part Manufacturers

This is a partial list of aerospace manufacturers by process type. For a

more extensive list see sources such as the annual Composites World

Sourcebook [www.compositesworld.com/].

54

method company

Manual Layup/

Autoclave Mold

Spirit Aerosystems

GKN-AL

ITT Integrated Structures

Vermont Composites

V Systems

Hexcel

Kaman

Matrix

Cobham [ex Sparta]

Tighitco

www.spiritaerosystems.com

www.gknaerospace.com

www.defense.itt.com

www.vtcomposites.com

www.vsc-inc.com

www.hexcel.com

www.kamanaero.com

www.matrixcorp.com

www.composites.sparta.com

http://www.tighitco.com/

Filament Winding Lincoln www.lincolncomposites.com

Pultrusion Kazak www.kazakcomposites.com

Automated Tow Placement/

Autoclave Mold

Vought

ATK

Hitco

www.voughtaircraft.com

www.atk.com

www.hitco.com

Finished Part Manufacturers

55

Method Equipment Maker

Compression

Molding Press

Wabash

Pacific Press

Technical Machine Products

www.wabashmpi.com

www.pacific-press.com

www.techmach.com

Autoclave Tarrico

American Autoclave

ASC Process Systems

www.tarrico.com

www.americanautoclave.com

www.aschome.com

Automated Fiber

Placement Machine

MAG Cincinnati

Ingersoll

Automated Dynamics

Electroimpact

Accudyne

www.mag-ias.com

www.ingersoll.com

www.automateddynamics.com

www.electroimpact.com

www.accudyne.com

Finished Part Manufacturing Technology Providers

This is a partial list of equipment manufacturers by equipment type. For a

more extensive list see sources such as the annual Composites World

Sourcebook [www.compositesworld.com/].

56

Method Equipment Maker

Filament Winder Entec

McClean Anderson

www.entec.com

www.mccleananderson.com

Oven Wisconsin

Grieve

www.wisoven.com

www.grievecorp.com

Robotic Ply Layup Composite Systems

Diaphorm

www.compositemfg.com

www.diaphorm.com

Finished Part Manufacturing Technology Providers

57

Equipment Makers

Ply Projection Virtek

LAP Laser

Anaglyph

Laser Projection Technologies

Assembly Guidance Systems

www.virtek.ca

www.lap-laser.com

www.anaglyph.co.uk

www.lptcorp.com

www.assemblyguide.com

Ply Cutters Gerber

American GFM

Eastman

www.gerbertechnology.com

www.agfm.com

www.eastmancuts.com

RTM Injectors Radius

Graco/Liquid Control

www.radiusengineering.com

www.graco.com

Non-contact

Dimensional

Measurement

Stienbichler

Creaform

Twin Coast

www.steinbichler.de

www.creaform3d.com

www.twincoastmetrology.com

Ancillary Manufacturing Methods

This is a partial list of equipment makers by equipment type. For a more

extensive list see sources such as the annual Composites World

Sourcebook [www.compositesworld.com/].

58

Equipment Makers

Laminate

NDI

• Physical Acoustics - Acoustic Emmission

• Imperium - Digital Acoustic Video

• A2 - Exoscan handheld FTIR

• Evisive - Microwave Scanning

• LSP Technologies - Laser Bond Inspection

• Photo Emission Tech - UV Surface Excitation

• Advanced Structural Imaging - Computer-Aided Tap Test

• Boeing - Mobile Automated Ultrasonic Scanner [MAUS]

• Digiray - Motionless Laminography X-Ray

• Steinbichler - Laser Shearography

www.mistrasgroup.com

www.imperiuminc.com

www.a2technologies.net

www.evisive.com

www.lsptechnologies.com

www.photoemission.com

www.asi-nde.com

www.boeing.com

www.digiray.com

www.steinbichler.de

Inspection Methods

59

Equipment Makers

Laminate

NDI

• Laser Technology - Laser Shearography

• Thermal Wave Imaging - Pulsed Thermography

• Wichitech - Electronic Digital Tap Hammer

• Quality Material Inspection - Air-coupled Ultrasound

• Honeywell International - Structural Anomaly Mapping

System [SAM], acoustic/laser

• Lockheed - Laser Ultrasonic Technology

• PaR Systems - Laser Ultrasonic Technology

• iPhoton - Laser Ultrasonic Technology

• Mitsui Engineering - Woodpecker automated tap tester

• Sonatest - Ultrasonic wheel probe array

www.laserndt.com

www.thermalwave.com

www.wichitech.com

www.qmi-inc.com

www.honeywell.com

www.lockheedmartin.com

www.par.com

www.iphoton.com

www.mes.co.jp

www.sonatest.com

Inspection Methods

60

Precursor Manufacturing Technology Providers

Equipment Makers Equipment Users

Uniweave, Dry &

Prepreg

Western Advanced Engineering Hexcel, Cytec, Nelcote, APCM, YLA

Plain & Satin Weave,

Dry & Prepreg

numerous Textile Products Inc, Hexcel

Braid, Dry Wardwell, Steeger, Hacoba, Herzog ITT, A&P, Bally Ribbon, Albany

Techniweave, Fabric Development

Non Crimp Fabrics Liba, Malimo, Mayer Saertex

Filament Wind Entec, McClean Anderson Lincoln

3D Weave 3TEX 3TEX, Bally, Fabric Development,

TEAM, Albany Techniweave

Stitched Fabrics, Dry Puritan Boeing

Z-pins, Prepreg Albany Techniweave

This is a partial list of manufacturers by material type. For a more

extensive list see sources such as the annual Composites World

Sourcebook [www.compositesworld.com/].

61

Activity Issues

Ply Layup & Forming • Need automation; constitutes large portion of part

fabrication labor.

Part Trimming • Labor content and accuracy can be improved by multi-

axis CNC.

Nondestructive Evaluation

• Laminate integrity

• Cure state

• Ply Angle Verification, Post-Cure

• Need a nondestructive method to verify ply angles and

ply boundaries.

• Need NDI instruments that can reach into tight spaces.

• Need to map defects into 3D CAD files.

Physics-Based Process Simulations

• RTM – avoid dry spots, resin

racetracking, local exotherm

• Compression Molding – avoid „horsetails‟

expelled from mold

• Autoclave Flow – ensure thermal

uniformity with an arbitrary loading of

parts

• Need software to be more user-friendly for front-line

engineers.

• Need to quantify material processing parameters

accurately.

Mold Design for In-tolerance Parts • Use physics-based design tool to account for warping

[see Convergent Manufacturing Technologies, Inc].

• Need to quantify material parameters accurately.

Issues With Manufacturing Processes

62

Issues With Manufacturing Processes

Activity Issues

Molecular Sensors For Process Control.

•fiber optic

•dielectric

• Better control than a canned time/temperature profile.

• Need user-friendly systems to install in production

molds.

• Need accurate material characterization.

• Need affordable systems.

Prepreg Perishability • Avoid manual data logging. RFID is being applied to

insure that material is used on time.

Out-of-Autoclave Curing • Reduce energy consumption and capital expense of

pressure vessel.

• Need materials designed for vacuum-only cure cycles.

Resin Cure Time • Resins typically need multi-hour cure cycles. This

requires multiple molds and curing systems for high-

rate production.

RTM with Intractable Resins • High viscosity, short pot life

• Advanced cure cycles – sum up the viscosity dips

• Port configuration – thru-thickness flow

• Combination - sequential porting

63

Emerging Methods for

Composite Manufacturing

64

Roctool Inc

http://www.roctool.com/

Rapid heating by an array of induction heads.

Quickstep Inc

http://www.quickstep.com.au/what-is-

quickstep

Applies heat and pressure by liquid instead of gas

for quicker heat transfer.

2PHASE Inc

http://www.2phasetech.com/

Reconfigurable mold surface for rapid prototyping or

repairs.

Electron Beam Curing

www.ebeamservices.com

www.acsion.com

Quick cure without thermal effects. Need radiation

shielding and resins designed for this process

3D Shape Weaving [Shape3 Inc]

http://www.shape3.com/

Seamless net-shape preforms; no cut fibers.

P4 Process

http://www.compositecenter.org/index.php/r

apid-fiber-preform.html

Discontinuous fibers applied onto molds in controlled

patterns to avoid manual ply layup.

Out-Of-Autoclave processes

http://www.advanced-

composites.co.uk/PSG_Electronic_Files/A

erospace_PSG_Files/outofautoclave.html

Prepreg materials are being developed to enable

curing and acceptable properties without the capital

investment for an autoclave.

Emerging Manufacturing Technology

65

Induction heating is used to selectively

heat the mold for rapid cycling and low

energy use compared to conventional

heating. This is used for RTM with dry

preforms and compression molding with

prepregs.

Size: custom-designed.

Roctool

66

This is a self-contained molding system

with a rapid heatup/cooldown system.

Molds float in a liquid media, so molds

require less stiffness than in other cure

processes. It can be used for bagging

processes such as autoclave/prepreg,

VARI and RFI.

Size: up to 20 sq yd area.

Quickstep Molding System

Mold

Controls

Tanks for liquid

pressure and heating

media

67

This is a reconfigurable mold that uses a

liquid/particle media contained by a

membrane that solidifies against a master

shape. The media can be re-liquified and

re-solidified, and can potentially be

sculpted to net shape with a CNC

machine. Molds up to several feet on a

side by 2 feet deep have been delivered.

Reconfigurable Mold, 2Phase, Inc

68

Net-Shape Weaving

Net shape contoured weaving has been

demonstrated by Shape3, but has not

been in high rate production. To cure the

final composite a process such as VARI

would be used.

http://shape3.com/

69

Electron Beam Curing

Composites are cured without heat in

a radiation-shielded accelerator. The

beam is scanned over the entire part.

Only resins designed for e-beam cure

can be used. Molds can be made

from wood or rigid foam.

•see www.acsion.com

70

Discontinuous Fiber Preforming, P4 Process

Chopped, tackified fiber is sprayed onto a

porous vacuum form with a CNC robot. The

preform then goes into an RTM mold for resin

injection and cure. This reduces labor content

and increases deposition speed compared to

hand layup. Somewhat lower mechanical

properties result than with continuous fibers.

Vacuum mold

Chopper/sprayer

71

Composite Manufacturing

Process Design and Modeling

Software Solutions

72

Composite Processing: Steps & Simulations

Simulation tools are becoming available to assist manufacturing engineers. Orient Fibers

draping

tow placement

nesting

geometry & motion

Resin Flow

reaction kinetics

heat flow

viscosity kinetics

fiber compaction

geometry, coupled diff e's,

molecular mobility sensing

Heat Resin

reaction kinetics

thermal & chemical eq's

Resin Cure

reaction kinetics

Heat flow

CTE build

Tg build

modulus build

resin bulk shrinkage

geometry, coupled diff e's

Cooldown

residual stress buildup

geometry, coupled diff e's

Demold

remove constraints

relieve stress

residual deformation

geometry, coupled diff e's

Mix Resin

reaction kinetics

chemical eq's

COTS Software

Raw Materials

Into Service

Design

intent

achieved

Machining

remove material

relieve stress

residual deformation

geometry, coupled diff e's

73

Features Web Site

NX

[formerly UG]

Has fabric draping features and

micromechanics calculator.

www.plm.automation.siemens.com

CATIA Dassault product, has fabric draping,

integration between design/analysis/

manufacturing.

www.3ds.com

Pro-E Sister product is Pro Mechanica FEA. www.ptc.com

CAD Tools

Not all CAD tools can easily handle composite ply information.

Here are some that do:

74

Features Web Site

ANSYS General purpose, has composite

elements

www.ansys.com

NASTRAN General purpose, has composite

elements

www.mscsoftware.com

www.plm.automation.siemens.com

ABAQUS General purpose, has composite

elements. Affiliated with

Dassault/CATIA.

www.simulia.com/products/abaqus_fea

MARC Good for nonlinear materials www.mscsoftware.com/products/marc.cfm

?Q=131&Z=396&Y=400

Pro-E/

Mechanica

Sister product of Pro-E, has

composite laminate features

www.ptc.com/products/proengineer/advan

ced-mechanica

LS-DYNA Impact & crash simulation www.lstc.com/lsdyna.htm

Lusas General purpose, has composite

elements

www.lusas.com/products/composite

ARPPAS Specialized package for repairs http://www.fea-llc.com/

StressCheck Has composite laminate features www.esrd.com

Structural Finite Element Analysis Software

75

CAD & FEA Translators

Features Web Site

Altair - Hypermesh CAD defeaturing and

repair, mesh generation

http://www.altairhyperworks.co

m/Product,7,HyperMesh.aspx

Elysium - CADdoctor CAD defeaturing and

repair

http://www.elysiuminc.com/

Anark convert and transform

3D CAD and related

product information

http://www.anark.com/

Due to the large number of software packages and vendors on the market,

there is an industry issue of file compatibility and interoperability. Supply chain

companies frequently encounter errors when converting surface and mesh data

from customers, needing time-consuming repairs before proceeding with the

value-added tasks at hand.

Tools exist to ease file translations between CAD and FEA formats. Some are

listed here:

76

Examples of Mold Flow Simulation

Vacuum Infusion

• How much time will it take to fill?

• Will gravity affect the fill process?

Matched Mold Injection

• Where should the runners be placed?

• How much pressure will it take to fill?

77

Type Features Web Site

RTM Flow

PAM-RTM Resin flow, fabric draping, reacting

resin, transient heating.

www.esi-group.com/products/composites-

plastics/pam-rtm

LIMS Resin flow www.ccm.udel.edu/Pubs/techbriefs/LIMS.pdf

RTM-Worx Resin flow www.polyworx.com

Composite Cure Springback

COMPRO Plug-in to ABAQUS and MARC,

calculates residual stresses and

springback due to resin cure.

Point solutions for resin cure can

be obtained using their Raven

package.

www.convergent.ca/products/compro%203d/

overview.html

Finite Element Based Process Simulation Tools

Physics-based models can be applied to arbitrary shapes. Proper simulation

requires that the processing properties of the materials be quantified in the code.

78

Example of Springback Simulation

• Composite resins shrink much more

than the fibers when curing.

• Thermal expansion of some mold

materials is much different than the

composite.

• When a simple 0/90 ply layup is

molded on a flat plate, the cured

part springs into a curved shape.

• This behavior can require re-

machining the mold after the first

part is made and measured.

• Simulations can be done to account

for this; to design the mold surface

properly in the first place.

90° ply

0° ply

Flat mold

79

Fabric Draping and Flat Patterns

Flat Pattern

A

B

Draped on Hemisphere

A B

A unique feature of composite fiber plies is that they shear and skew

as they are placed onto a contoured mold. Since fiber angles

drastically affect mechanical and processing properties, both the

designer and the manufacturer need to specify and control this

behavior. The flat cutting patterns depend on the draping behavior.

Software packages exist to plan the plies correctly.

Fibers at B are

highly skewed

on the mold

80

Type Features Web Site

Fabric Draping and Flat Patterns

Fibersim Plug-in to NX, CATIA, Pro-E. www.vistagy.com

Laminate Tools Stand-alone CAD/FEA interface for

composite plies.

www.anaglyph.co.uk

Simulayt Plug-in to CATIA/ABAQUS. www.simulayt.com

PAM-RTM/Quickform Part of PAM-RTM. www.esi-

group.com/products/composites-

plastics/pam-rtm

Interactive Drape Interactive, inexpensive fabric draping

simulator.

www.interprot.com/

Patran/Laminate Modeler Has fabric draping function. www.mscsoftware.com

‘Soup to Nuts’

ITOOL European effort to model fabric unit

cells, fabric draping, RTM flow and

structural response.

www.itool.eu

Process Simulation Software Tools

Geometry-based tools can be applied to neutral CAD surfaces and FE meshes.

81

Type Features Web Site

Filament Winding

Entec Models tensioned fibers on a

rotating mandrel.

www.entec.com/

CADWIND Models tensioned fibers on a

rotating mandrel.

www.material.be/filament-winding-

software

Auto Tape Laying, Auto Fiber Placement

Vericut Can model various machines. www.cgtech.com

Fiber Placement Expert

System

Can model various machines. www.compositepro.com/Fipes.html

ACES By MAG Cincinnati for their

machines.

http://cinmach.mag-

ias.com/products/automated-

composites-processing/aces

Process Simulation Software Tools

82

Features Web Site

Composite Pro Calculator to determine stiffness

properties of laminates, and structural

response of simple shapes.

www.compositepro.com

Helius Calculator to determine stiffness

properties of laminates. Will be adding

textile composites.

www.fireholetech.com

Texcad,

mmTexlam

Calculator to determine stiffness

properties of textile composites. K. Shivakumar [kunigal@ncat.edu]

ITOOL Determine stiffness properties of textile

composites

www.itool.eu

Hypersizer Calculator to determine stiffness

properties of laminates, and structural

response of simple shapes.

www.hypersizer.com

Sysply Calculator to determine stiffness

properties of laminates

www.esi-

group.com/products/composites-

plastics/sysply

Laminate Property Calculation

83

Connecticut Center for Advanced Technology www.ccat.us

University of Delaware Center for Composite Materials www.ccm.udel.edu

University of Dayton Research Institute www.udri.udayton.edu

Air Force Research Lab, Materials Directorate www.wpafb.af.mil/afrl/rx

NASA, Langley & Glenn Research Centers www.nasa.gov/centers/langley/home/index

www.nasa.gov/centers/glenn/home/index

National Composite Center www.compositecenter.org

Composites Manufacturing Technology Center http://cmtc.scra.org/about_cmtc.shtml

National Institute for Aviation Research www.niar.wichita.edu/researchlabs/comp_ov

erview.asp

National Center for Manufacturing Sciences www.ncms.org

Composites Manufacturing Technology Center http://cmtc.scra.org/tcc_overview.shtml

Composite Materials Resource Centers

84

Composites World

Magazine

Covers a wide range of

design/analysis/manufacturing topics.

Publishes annual supplier listing.

www.compositesworld.

com/

Journal of Composite

Materials

Peer-reviewed academic journal. http://jcm.sagepub.com

American Society for

Metals

Publishes detailed handbooks on various

materials. For composites see ASM Handbook

Volume 21.

asmcommunity.asminte

rnational.org/portal/site/

www/

Society for the

Advancement of Material

and Process Engineering

Conducts annual conferences on composite

properties, design and fabrication.

www.sampe.org

Society of Manufacturing

Engineers/Composites

Group

Conducts annual conferences on tooling and

manufacturing

www.sme.org

Consortium for

Improving/Integrating

Advanced Composites

Processes (CIACP)

Brings together design and manufacturing

technologies.

Conducts regional conferences.

www.agfm.com/Initiativ

es/CIACP.htm

American Society for

Composites

Promotes the exploitation of the unique

properties of composite materials in emerging

applications.

www.asc-

composites.org

Composite Materials Associations & Publications