Composite Materials- Composite Materials- Research and ApplicationsResearch and Applications Dr. K. Padmanabhan, FIIPE, FIE, CE(I), FISME.Dr. K. Padmanabhan, FIIPE, FIE, CE(I), FISME.

ProfessorProfessorSchool of Mechanical and Building SciencesSchool of Mechanical and Building Sciences

Vellore Institute of Technology-UniversityVellore Institute of Technology-UniversityVellore 632014Vellore 632014

DefinitionDefinition

A composite material is a multi-A composite material is a multi-component system with at least a matrix component system with at least a matrix and a reinforcement.and a reinforcement.

The desired properties must be better than The desired properties must be better than at least one of the constituents.at least one of the constituents.

The constituents are normally physically The constituents are normally physically separable , with a line of heterogeneity separable , with a line of heterogeneity between them, called the interface.between them, called the interface.

ContentsContents

ApplicationsApplications MicromechanicsMicromechanics Meso and MacromechanicsMeso and Macromechanics Modelling and SimulationModelling and Simulation Mechanical TestingMechanical Testing Fracture, Failure Theories and DesignFracture, Failure Theories and Design Design PhilosophyDesign Philosophy Summary Summary

Composites in Wind EnergyComposites in Wind Energy

www.suzlon.com , www.ge.com Vestas RRB

Composites in StorageComposites in Storage

Corrosion and weathering free thermoset and thermoplastic matrix glass fibre reinforced composite storage tanks, pressure vessels and containers are cheaper and more durable than conventional containers

Roads with Plastic WastesRoads with Plastic Wastes

Fuel from Plastic WastesFuel from Plastic Wastes

Biomedical CompositesBiomedical Composites

s

75X106 cyles of heart beat 78 x 106 cycles of heart beat over 25 years

Composites in DentistryComposites in Dentistry

Acrylics, Acrylic esters, Bis-GMA, PMMA derivatives, Ceramic filled composites

Can you make out the difference ?

Ref: K. Padmanabhan , Programme overview, NIST ceramics machining consortium, I th Chapter, Gaithersburg, USA, October 8-9, 1998.

Composites in AutomobilesComposites in Automobiles

Italian automobile with carbon fibre composite chassis

All Composite EnginesAll Composite Engines

Aluminium Composite Engine

Composite Engine Manifold

All composite AircraftsAll composite Aircrafts

Indian Hansa-All composite aircraft

VTOL Aircraft

Ref: B.K. Parida, RMVGK Rao and K. Padmanabhan , Proceedings of the third joint National Aerospace Laboratories- Chinese Aircraft Establishment workshop on composites, April 22-24, Bangalore, India, 1996, p9. & NAL website

Composites - Sports & LeisureComposites - Sports & Leisure

Carbon fibre-nylon matrix – rigid foam tennis racquet

Composite Yatch

Composites in DefenseComposites in Defense

A Bulletproof Vest A missile material case

Composites in SpaceComposites in Space

All aluminium alloy and carbon composites

Micromechanics is where Micromechanics is where design begins !design begins !

Design is defined as the complete information required to produce a product - Anonymous

The Fibre-Resin Micro bondThe Fibre-Resin Micro bond

                                                                                                            

A drop of the cured resin on the fibre surface showing adhesion

Fibre pullout test through a micro vise design fixture

Micro bond Bundle Pull-out TestMicro bond Bundle Pull-out Test

Ref: K. Padmanabhan , Final project report to the Singapore –MIT Alliance ,Singapore, November 2002

Interface TestsInterface Tests

Single fibre pullout testSingle fibre pullout testSingle fibre push out test, brittle materialsSingle fibre push out test, brittle materialsMicro bond single fibre pullout testMicro bond single fibre pullout testMultiple fibre pullout test and Micro bond Multiple fibre pullout test and Micro bond multiple fibre pullout test, Statistically multiple fibre pullout test, Statistically averaged results, More precise, Less averaged results, More precise, Less difficult, Mesomechanical in nature. difficult, Mesomechanical in nature. Interlaminar shear strength test, ILSS.Interlaminar shear strength test, ILSS.

Multiple Fibre PulloutMultiple Fibre Pullout

Ref: K. Padmanabhan , Toyobo Confidentiality Report, 2002.

Ref: C. Y. Yue and K. Padmanabhan , Composites B, 30(1999) p205.

Micro bond Matrix slab

Modelling and AnalysisModelling and Analysis

Carbon Fibre and ZylonCarbon Fibre and Zylon™™ Fibre /epoxy Fibre /epoxy Matrix Embedded Composite SystemsMatrix Embedded Composite Systems

Cylindrical Assemblage Model

Matrix

Pull Out Through a Micro vise

• Micromechanics

le

Interfacial ParametersInterfacial Parameters

Interfacial shear strength,Interfacial shear strength,ττ

Interfacial frictional stress, τInterfacial frictional stress, τff

Fibre/matrix coefficient of friction, µFibre/matrix coefficient of friction, µ

Matrix shrinkage pressure, PMatrix shrinkage pressure, Poo

Pressure due to Poisson expansion, pPressure due to Poisson expansion, paa

Contact pressureContact pressure

Interfacial wearInterfacial wear

Non-linear Quasistatic Non-linear Quasistatic AnalysisAnalysis

Surface to surface Surface to surface contactcontactCAM is anisotropic CAM is anisotropic and matrix is isotropicand matrix is isotropicOnly failure and post Only failure and post failure conditions were failure conditions were considered due to considered due to relevance and precision relevance and precision Model has dihedral Model has dihedral symmetrysymmetry

Solid 8 noded brick 185 element Hex swept volumes

Results of ANSYS AnalysisResults of ANSYS Analysis

37 MPa

Zylon/epoxy shear stress at CAM interface

FEM Analysis ResultsFEM Analysis Results

Carbon/epoxy shear stress at CAM interface

Micro buckling and DesignMicro buckling and Design

Micro buckling can be Micro buckling can be prevented by choosing prevented by choosing higher fibre diameter, higher fibre diameter, higher fibre elastic higher fibre elastic modulus and high modulus and high interfacial bond strength interfacial bond strength between fibre and matrixbetween fibre and matrix

Boron fibres are the best Boron fibres are the best for design against micro for design against micro bucklingbuckling

MacromechanicsMacromechanics

Transversely isotropic Transversely isotropic composite needs 5 composite needs 5 independent elastic independent elastic constants for efficient constants for efficient modelling (UD/0modelling (UD/00 0 ))

Layered orthotropic Layered orthotropic composite needs 9 composite needs 9 independent elastic independent elastic constants for efficient constants for efficient modellingmodelling

3 D Braided Structures3 D Braided Structures

3 D braided ,knitted, stitched and fibre preform structures have enabled easy manufacturing of net shape FRPs. The modelling and performance analysis of such structures poses challenges

Failures and Multiple CausesFailures and Multiple Causes

In nature, most of the real environment failures In nature, most of the real environment failures are due to multiple causes.are due to multiple causes. As enough standard procedures are available As enough standard procedures are available for failures due to a single cause, the obvious for failures due to a single cause, the obvious move is to develop the understanding as well as move is to develop the understanding as well as standard procedures for failures due to multiple standard procedures for failures due to multiple causes.causes.An understanding of these failures leads to a An understanding of these failures leads to a better fracture control that aids superior designs better fracture control that aids superior designs with advanced composite materialswith advanced composite materials

Mechanical TestingMechanical Testing

Ref: K. Padmanabhan and Kishore , ` Failure behaviour of carbon/epoxy composites in pin ended buckling and bending tests’, Composites, Vol:26,No: 3, 1995, p201.

Bolted and Bonded Composite Bolted and Bonded Composite JointsJoints

Joint testing of a composite lug

Fracture Mechanics TestingFracture Mechanics Testing

Mixed mode testing of compositematerials is a recent trend as causes are multiple during failure in real conditions

Fracture mechanics tests to evaluate fracture toughness and strain energy release rates have found quite a few standards in ASTM

Composites in Microelectronic Composites in Microelectronic PackagingPackaging

The BOM includes Copper lead frame,Gold wires for bonding, Silver –epoxy for die attach, Silicon die and Epoxy mould composite with Phenolics, Fusedsilica powder and Carbon black powderas the encapsulant materials.

Thermal – Structural ResultsThermal – Structural Results

Displacement Vector sum Von mises stress

Stress intensity XY Shear stress

Non Destructive EvaluationNon Destructive Evaluation

Ultrasonic C-Scan NDT can do depth profiling of composites delamination and damage profiling

Scanning acoustic microscope can sense delaminations of micron dimensions ( shown as red areas) in TQLMP IC packages. FEA techniques are also NDE techniques.

Composites in ProsthodonticsComposites in Prosthodontics

Tooth is a functionally gradedcomposite material with enameland dentin. In the third maxillary molar the occlusal stress can be 2-3 MPa.

The masticatory heavy chewing stress will be around 193 MPa.A composite restorative must with stand this with an FOS and with constant hygrothermal attack.

Hygrothermal BehaviourHygrothermal Behaviour

Fibre reinforced plastics are known for Fibre reinforced plastics are known for environmental attacks that reduce their function.environmental attacks that reduce their function.Mechanical properties degrade over time !Mechanical properties degrade over time !Moisture plays havoc at elevated temperatures, Moisture plays havoc at elevated temperatures, in the presence of voids, defects and in low Tin the presence of voids, defects and in low Tgg plastics .plastics .Diffusion and osmotic pressure are the driving Diffusion and osmotic pressure are the driving mechanisms for hygrothermal attackmechanisms for hygrothermal attackEvaluation methods and surface preservation Evaluation methods and surface preservation Important in marine, biomedical, aeronautical, Important in marine, biomedical, aeronautical, electronic and automobile applications electronic and automobile applications

Azzi-Tsai-Hill Failure TheoryAzzi-Tsai-Hill Failure Theory

Where, σ11 = X ( tensile / compressive) stress in MPa σ22 = Y ( tensile / compressive) stress in MPaτ12 = Shear stress in MPaSLt = Longitudinal tensile strength in MPaSTt = Transverse tensile strength in MPaSLts = In-plane shear strength in MPa

Tsai – Wu Failure TheoryTsai – Wu Failure Theory

F1 σ11 + F2 σ22 + F6 τ12+ F11 σ112+ F22 σ22

2+ F66 τ122+2 F12 σ11σ22 = 1

Where,Other parameters / symbols appear on the previous slide,SLc = Longitudinal compressive strength in MPaSTc = Transverse compressive strength in MPa.

ASTM STP D 5229 M RuleASTM STP D 5229 M Rule

The MOT( Maximum Operating Temperature) The MOT( Maximum Operating Temperature) of the material, device/component should be of the material, device/component should be at least at least 25 º Celsius lower than the lowest Tg (normally wet) of the material attained after hygrothermal equillibration. All the polymeric . All the polymeric materials and their composites must satisfy materials and their composites must satisfy this rule in order to qualify for certification for this rule in order to qualify for certification for reliability and durability.reliability and durability.

Sandwich Core MaterialsSandwich Core Materials

Foam

Honeycomb

Sandwich Showing Core and Sandwich Showing Core and Skin –Core Interfacial FailureSkin –Core Interfacial Failure

Tensile faceCore failure

Ref: ASTM C 393/C393M-06, ASTM D7249/ D 7249 M-06, ASTM D7250/ D7250M-06

Advances in Sandwich Advances in Sandwich CompositesComposites

•Develop fracture mechanics test methods for sandwich composites•Focus on facesheet core delamination•Both Mode I and Mode IISuitable for ASTM standardization

Ref: Dan Adams, Department of Mechanical Engg , Department of Mechanical EngineeringUniversity of Utah, Salt Lake City, UT, USA

Design OptimizationDesign Optimization

Ref: 1. G.R. Froud ,Composites, July, 1980, p 133 2. RMVGK Rao et al in Jl. Of Reinforced Plastics and Composites, Vol:25, No: 6, 2006, p 663

Design Optimization for StrengthDesign Optimization for Strength

Glass-Epoxy Skin ShowingBuckling Delamination Type Of Failure on the CompressiveFace.

Carbon-Epoxy Skin ShowingBuckling Delamination Type Of Failure on the CompressiveFace.

Skin Weight= Core Weight

Zylon FibreZylon Fibrewww.toyobo.co.jpwww.toyobo.co.jp

ZYLON   consists of rigid-rod chain molecules of poly(p-phenylene-2,6-benzobisoxazole)(PBO).

Tensile Strength : 5.8 GPa

Tensile Modulus : 270 GPa

Ref: K. Padmanabhan , Toyobo Confidentiality Report, 2002.

NanocompositesNanocomposites

The SWNT has a Tensile Modulus of 1-5 TPa and a Tensile Strength of 13-53 GPa at an elongation of 16 %. A 0. 50 Vf composite , in theory will have a tensile strength and a modulus around half as much, assuming that the matrix is weak !

Carbon nanotubes

Design Philosophy- Design Design Philosophy- Design PropertiesProperties

Strength, Stiffness, Toughness, Fatigue, Creep, Strength, Stiffness, Toughness, Fatigue, Creep, Impact and Damage toleranceImpact and Damage tolerance

Dimensions, Weight, TolerancesDimensions, Weight, Tolerances

Judicious use of drafts, radii, fillets, webs, ribs, Judicious use of drafts, radii, fillets, webs, ribs, blends, chamfers and curves for specific blends, chamfers and curves for specific propertiesproperties

Ease of assembly, disassembly and serviceEase of assembly, disassembly and service

Aesthetics, colouring and texturing, Eco friendly Aesthetics, colouring and texturing, Eco friendly designdesign

Design Philosophy- Design Philosophy- Manufacturing PropertiesManufacturing Properties

Forming temperature, Glass transition, Melting Forming temperature, Glass transition, Melting point, Rate of solidificationpoint, Rate of solidification

Energy required to form, Whether batch process Energy required to form, Whether batch process possible? , Pressure requiredpossible? , Pressure required

Flow behaviour, Viscosity, Melt flow indexFlow behaviour, Viscosity, Melt flow index

Mouldability and Castability, WorkabilityMouldability and Castability, Workability

Fabrication of Complex Parts, TimeFabrication of Complex Parts, Time

Curing/Solidification Shrinkage in the MouldCuring/Solidification Shrinkage in the Mould

Materials properties, Availability, Toxicity, SafetyMaterials properties, Availability, Toxicity, Safety

Design Philosophy- Design Philosophy- Customer RequirementsCustomer Requirements

Quality, Cost, Durability ( low moisture Quality, Cost, Durability ( low moisture absorption), Reliability ( low degradation of absorption), Reliability ( low degradation of properties with time)properties with time)

Efficiency : Better properties at lighter Efficiency : Better properties at lighter weight and less money, Valueweight and less money, Value

Flexibility : Multi functionalityFlexibility : Multi functionality

Low maintenance costLow maintenance cost

Aesthetics, textures in DesignAesthetics, textures in Design

Design PhilosophyDesign PhilosophyPyramidal SubstantiationPyramidal Substantiation

The aircraft ,we hope, is never tested

The sub-assemblies and the assemblies

are tested the least

The subcomponents and components are tested less often

The test specimens are tested more often

BibliographyBibliography

P,K. Mallick, Fibre reinforced composites, Marcel and P,K. Mallick, Fibre reinforced composites, Marcel and Dekker Inc., New York .Dekker Inc., New York .

Derek Hull and T.W. Clyne, ` An Introduction to Derek Hull and T.W. Clyne, ` An Introduction to composite materials’, Cambridge solid state science composite materials’, Cambridge solid state science series, 1996.series, 1996.

E.J. Barbero, `Introduction to composite materials E.J. Barbero, `Introduction to composite materials design’, Taylor and Francis ,MI.design’, Taylor and Francis ,MI.

J.K. Kim and Y.W. Mai, `Engineered interfaces in fibre J.K. Kim and Y.W. Mai, `Engineered interfaces in fibre reinforced composites ‘, Elsevier, 1998.reinforced composites ‘, Elsevier, 1998.

www.wikipedia.orgwww.wikipedia.org

Rao Tummala, Microsystems Packaging,McgrawHill.Rao Tummala, Microsystems Packaging,McgrawHill.

BibliographyBibliography

Sanjay K Mazumdar, Composites Manufacturing, CRC Sanjay K Mazumdar, Composites Manufacturing, CRC Press, 2002.Press, 2002.Geoffrey Pritchard, Reinforced Plastics Durability, Geoffrey Pritchard, Reinforced Plastics Durability, Woodhead publishing,Cambridge, England, 1999.Woodhead publishing,Cambridge, England, 1999.Skinner’s Science of Dental Materials , R.W. Phillips, A Skinner’s Science of Dental Materials , R.W. Phillips, A Prism India ed, 1994.Prism India ed, 1994.ASTM Standards Handbooks Vols: 08.01,08.02 and ASTM Standards Handbooks Vols: 08.01,08.02 and 08.03, PA, USA.08.03, PA, USA. www.astm.orgwww.astm.orgANSYS v.11 Analysis Manuals, 2008.ANSYS v.11 Analysis Manuals, 2008.Rayner M Mayer, Design with Reinforced Plastics, Rayner M Mayer, Design with Reinforced Plastics, Design Council, London.Design Council, London.

BibliographyBibliography

K. Padmanabhan, S.Subeesh, K. Balaguru and T. K. Padmanabhan, S.Subeesh, K. Balaguru and T. Karthik , ` 3D Modelling and Failure Analyses of IC Karthik , ` 3D Modelling and Failure Analyses of IC packages’, in ANSYS Users’ Conference CD, 6 & 7 packages’, in ANSYS Users’ Conference CD, 6 & 7 November 2008, Bangalore. November 2008, Bangalore. K. Padmanabhan, S.Subeesh, K. Balaguru and T. K. Padmanabhan, S.Subeesh, K. Balaguru and T. Karthik , ` An Analyses of Reliability and Karthik , ` An Analyses of Reliability and Hygrothermal Effects in IC packages’, in ANSYS Hygrothermal Effects in IC packages’, in ANSYS Users’ Conference CD, 6 & 7 November 2008, Users’ Conference CD, 6 & 7 November 2008, Bangalore. Bangalore. BEST PAPER AWARDBEST PAPER AWARD K. Padmanabhan, D. Sanjay and S Subeesh,` Design K. Padmanabhan, D. Sanjay and S Subeesh,` Design and electro-hygrothermo-mechanical reliability and electro-hygrothermo-mechanical reliability analyses of a leadless quad IC package’, in theanalyses of a leadless quad IC package’, in the

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