iacmi student intern teams presentation

Intern and Student IACMI Focused Projects

July 28, 2016

Moderated by: Dr. Uday VaidyaIACMI, Chief Technology Officer and

University of Tennessee Governor’s Chair in Advanced Composites Manufacturing

3IACMI Overview

Agenda

• Overview

• Presentation of Projects

• Invitation to Meet Students at Poster Displays

4IACMI Overview

Student Presentations

5IACMI Overview

Wind Technology Area

Nicholas BradyVirginia Polytechnic and State UniversityBS Mechanical Engineering andMaterial Science Engineering

Hosted By:Colorado School of Mines andNational Renewable Energy Laboratory (NREL)

The Microencapsulation of Paraffin Wax in Polystyrene for Use in the Manufacturing of Thermoplastic Composites

Yasuhito Suzuki3, John Dorgan1,2,3, Derek Berry1,2

Background and Objective

Materials and Methods

Preliminary Results The general composite wind turbine blade weighs almost 7 tons and can be in

service for only about 20 years. Therefore, the recyclability of these blades is crucial to resource conservation and the proliferation of wind energy.

Composites with thermoplastic matrices provide a much higher reclamation ability than those with thermoset matrices.

Thermoplastic composites have curing difficulties at the large thickness required for turbine blades. Difficulties include exceeding the ideal temperature range for curing and temperature gradients within the matrix.

Phase change materials (PCMs) strategically embedded in the matrix would allow for more time spent in the ideal temperature range and stabilize the curing throughout the composite. To decrease the PCM’s effect on the mechanical properties, encapsulating a particle in a polymer similar to the thermoplastic matrix is ideal.

The goal of this research was create polystyrene microcapsules around a paraffin wax core with a high heat of fusion and low particle size.

Future Work

Mold for Siemens SWT-6.0-154 6 composite wind turbine blade

Experimental encapsulation setup

80x magnified image of capsulesCapsule Diameter

Mean= 324.506 μmS.D. = 146.387 μm

Research will be continued using a ter-polymerization of methyl methacrylate, methyl acrylate, and methacrylic acid to create the capsule. It is predicted that this will better match the matrix of the thermoplastic composite which will be polymethylmethacrylate, decrease particle size and increase the heat of fusion.

Additionally, adjusting the ratios of polyvinylpyrrolidone to water and paraffin wax to monomer will be done in order to maximize heat of fusion while decreasing the capsule size to around 100 μm. References

(1) Sánchez, Luz et al. "Microencapsulation of PCMs with a polystyrene shell". Colloid Polym Sci 285.12 (2007): 1377-1385.(2) Sánchez-Silva, Luz et al. "Synthesis And Characterization Of Paraffin Wax Microcapsules With Acrylic-Based Polymer Shells". Industrial &

Engineering Chemistry Research 49.23 (2010): 12204-12211.

1The Institute for Advanced Composite Manufacturing Innovation2National Renewable Energy Laboratory3Colorado School of Mines

Temperature Probe: 95°C

Stirring :600 RPM

Nitrogen Flow

Heating Plate & Oil Bath

Condenser

Phase Ingredient MassContinuous Phase Water 500.0 g

Polyvinylpyrrolidone 5.000 g

Discontinuous Phase Benzoyl Peroxide 1.675 g

Styrene 103.8 g

Paraffin Wax 35.80 g

To create encapsulated PCM microparticles, suspension polymerization was used. The continuous phase consisted of water and

a stabilizer, polyvinylepyrolidone. The discontinuous phase contained the

monomer styrene, an initiator Benzoyl Peroxide, and Paraffin Wax as the PCM.

TGA of PCM CapsulesΔHm = 186.2 J/g

ΔHm = 40.2 J/g

ΔHc = 184.7 J/g

ΔHc = 40.9 J/g

2016, Nicholas Brady, Virginia Polytechnic and State University, B.S. in 2019

To evaluate the produced microparticles, thermal analysis was performed using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Magnified images were inspected for particle size and shape.

The paraffin was successfully encapsulated in a shell of polystyrene. This can be demonstrated by the changes in percent mass seen in the TGA (A) and the much lower heat of fusion calculated from the DSC (B versus C). The particles were irregularly shaped with a large variance in the particle size (D).

Temperature (°C)

Temperature (°C)

Nor

mal

ized

Heat

Flo

w (W

/g)

DSC of Paraffin Wax at 10°C per min

DSC of PCM Capsules at 10°C per min

Nor

mal

ized

Heat

Flo

w (W

/g)

A)

B)

C)

D)

7IACMI Overview

Wind Technology Area

Sawyer BuckUniversity of Wisconsin-Eau ClaireBS Material Science with Physics Emphasis

Hosted By:Colorado School of Mines and theNational Renewable Energy Laboratory (NREL)

Methyl methacrylate (MMA) reacts with benzoyl peroxide (BPO) to form Poly methyl methacrylate(PMMA).

BPO (initiator)

Optimization of Polymerization of Polymethyl methacrylate (PMMA) From MMA, PMMA, and Amine Resin2016: Sawyer Buck, NREL/Colorado School of Mines, Junior BS University of Wisconsin-Eau Claire

Derek Berry (NREL), Professor Dorgan (CSM), Yasuhito Suzuki (CSM)BACKGROUND / OBJECTIVES

MATERIALS / METHODS

Summary• The effect of initiator concentration was tested and it was found that the

optimal value was between 1 and 3wt% BPO.

• The effect of initial viscosity was tested and it was determined that between 20 and 30wt% PMMA was the optimal value.

• This research reduces the cycle time of production as well as keeping the maximum temperature below the boiling point of MMA

• Wind turbines have a relatively short lifespan. This causes a problem when they must be discarded because the material used is a non-recyclable thermoset.

• The goal of the overall research is to use a thermoplastic instead so that when the lifespan is up, the material can be recycled.

• This poster focuses on optimizing the induction time for the polymerization of methyl methacrylate (MMA).

RESULTS

The mixture used consisted of 78wt% MMA and 22wt% PMMA with 0.5 mol% (with respect to MMA) Amine added.

0 10 20 30 40 50

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(o C)

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4 wt% 3 wt% 2 wt% 1 wt% 0.5 wt%

A) Initiator Concentration

0 10 20 30 40

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(o C)

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5 wt% 6 wt% 8 wt% 10 wt%

B) Initiator Concentration

1) Effect of Initiator Concentration

Reference: Polym. Chem., 2015, 6, 5721

0 20 40 60 80 100

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ture

(o C)

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Addition of PMMA 0 wt% 5 wt% 10 wt% 20 wt% 30 wt%

C)

2) Effect of Change in Viscosity

Similar mixture was used as when testing the initiator concentration except the wt% of PMMA varied

AmineBenzoyl Peroxide

9IACMI Overview

Design, Modeling, & Simulation Technology Area

William HenkenUniversity of Central FloridaBS Aeronautical Engineering

Hosted By:Purdue University

William HenkenAeronautical Engineering

University of Central Florida

From Gainesville Florida Expected Graduation Fall 2017

Design and Production of a Composite Hyperloop Shell Prototype

12IACMI Overview


Georgia HurchallaMichigan Tech, BS Materials Engineering


Georgia HurchallaSterling Heights, MI

Materials Engineering, 2017

15IACMI Overview


Sam WilliamsWinona State University BS Composite Engineering


Sam WilliamsComposite Engineering, 2017

18IACMI Overview


Kelsey Wells University of Nebraska LincolnPhD Candidate Mathematics


Kelsey Wells Friends, Waffles, Work

21IACMI Overview

Vehicle Technology Area

Christopher HersheyMichigan State UniversityPhD Candidate Chemical Engineering

Hosted By:Michigan State University

USE OF LUBRICANTS IN INJECTION MOLDING CHOPPED FIBER REINFORCED POLYPROPYLENE

Christopher J. Hershey, Michigan State UniversityDr. K. Jayaraman, Michigan State University

INTRODUCTION PRELIMINARY RESULTS

TIMELINES / FUTURE WORK

• Compared to steel, carbon fiber composites weigh less and imbue greatermechanical strength in molded parts making them desired in theautomotive industry.

• High shear rates during injection molding lead to severe attrition of carbonfibers reducing the fiber length and the overall composite strength.

• This work aims to evaluate, by friction measurements and analyticalmodeling, a lubricant’s ability to dissolve existing carbon fiber sizingthereby creating an interfacial slip layer between the fibers and matrix toreduce the shear stresses which result in fiber breakage.

MATERIALS AND METHODS• AS4 12K tow un-sized carbon fiber is chosen as the base case for friction

tests. Industry supplied sized fibers are to be mixed with lubricant duringmelt mixing process to initiate sizing dissolution.

• Friction measurements are to be carried out using a TA instruments ARESrheometer equipped with a Sentmanat Extension Rheometer (SER) toverify the interfacial lubricating effect against a strip of polypropylene.

• Simulation results for fiber breakage are generated using Moldex3D, withbulk parameters adjusted to account for addition of lubricants.

A base case for fiber breakage was first developed using a computational aide, Moldex3D1 to determine which model parameters2 were most affected by the addition of a lubricating packet.

Simulation results illustrating the effect of lubricant addition on fiber breakage:(Left) Lubrication migration and dissolution of the existing sizing reduces thebulk and fiber interfacial viscosity causing a decrease in the drag coefficient3.This requires a higher critical shear rate needed to break the fibers.(Right) Simulated results detailing fiber breakage in extruder. A new modelincorporating lubrication migration would introduce a bulk viscosity andinterfacial viscosity making fiber breakage a superposition of these curves.

June 2016 July 2016 August 2016

Learn fundamentals ofCarbon Fiber Composites

Begin modeling work

Moldex3D Simulationsand

Interfacial Rheology (SER)

Lubricant Addition for Bulk Rheology Effect

REFERENCES1. Material Database, CoreTech System, Hsinchu, Taiwan, ( 2012).2. J.H. Phelps, A.I. Abd El-Rahman, V. Kunc and C.L. Tucker III, “A model for fiber length attrition in

injection-molded long-fiber composites,” Composites: Part A, 51, 11 (2013).3. T.J. Ui, R.G. Hussey and R.P. Roger, “Stokes drag on a cylinder in axial motion,” Phys. Fluids, 27, 787

(1984).

Internal/Bulk Effect• Overall reduction in

matrix viscosity• Resulting in lower matrix

properties• Lower Shear Stresses

Interfacial Effect• Partial dissolution of

existing sizing• Dependent on lubrication

migration to surface• Lower Interfacial Viscosity

Illustration of lubricant’s effect on carbon fiber composite. The lubricant is able to interact with the bulk matrix polymer to create an internal lubricating effect. Lubricant eventually

migrates to the fiber and dissolves the sizing creating an interfacial lubricating effect.

23IACMI Overview

Vehicle Technology Area

Kevin SchuettMichigan State UniversityBS Mechanical Engineering

Hosted By:Michigan State University

COMPUTATIONAL DESIGN OF REVERSIBLE ADHESIVE JOINTS Kevin Schuett, Michigan State University, 3rd Year Undergraduate Mechanical Engineering,

Suhail H Vattathurvalappil, Graduate Student, Civil Engineering, Mentor: Mahmood Haq

First, a model was created to match the elastic region(stiffness) for one GnP content (3 wt.%) . The rest ofexperimental data was successfully predicted.

The effects of platelet morphology and random dispersionwere successfully modeled.

Material nonlinearity, interface and damage modeling willallow for capturing the full behavior of the material.

1 https://www.linkedin.com/pulse/advances-metals-pave-way-lighter-vehicles-jeff-kernscar picReferences

2 http://www.growmaterials.com/recycle/ pellets 3 http://www.nanochemistry.it/ graphene

Multi material joining methods (composite to metal) in automotive applications are not fully understood

One approach that uses the benefits of both light weighting and re-assembly is:

Design space is HUGE! Can we eliminate trial-and-error approach?

Graphene nanoplatelet embedded Nylon has been successfully used in this work. GnPinteracts with microwaves to assemble/disassemble a joint.

Multi-scale modeling of the structural behavior of the joints taking into account the nanoparticle morphology and dispersion at the nanoscale.

Acknowledgements

Thermoplastics doped with conductive nanoparticles allows for targeted heating of adhesives when exposed to electromagnetic radiation. Adhesives melt rapidly and upon cooling forms a bond. Similarly the joints can be disassembled at will!

BACKGROUND & OBJECTIVES PRELIMINARY RESULTS

MATERIALS & METHODS TIMELINE & PATH FORWARD

IACMI – Internship Composite Vehicle Research Center

Prof. Lawrence T Drzal Dr. Ermias G Koricho

COMPOSITE

3D woven Carbon Preform Composite

Novel, Active, Nano-Graphene

embedded Adhesive

Steel / Aluminum

Task List and Progress June July August Sept.Literature review and backgroundIntro to modeling and materialsModeling of linear elastic behavior, material morphology and distribution ❶Model Damage ❷Structural Simulation (modeling joints, in plane and out of plane) ❸Design Tool: Predicting behavior beyond experimental matrix ❹

Progress❷ - Milestone

What concentration of GnP provides synergy of mechanical properties along with reversibility?

The goal is to create experimentally validated numerical models that will allow for accurate predictions beyond the experimental matrix to fully exploit the benefits offered by this tailorable material.

25IACMI Overview

Compressed Gas Storage Technology Area

Bretton BethelWright State UniversityBS Mechanical Engineering

Hosted By:University of DaytonResearch Institute

University of Dayton Research Institute Bretton Bethel, Jared Stonecash

OBJECTIVE: OBTAIN EXPOSURE TO KEY ENABLING MANUFACTURING PROCESSES IDENTIFIED BY IACMI/DOE

THERMOPLASTIC OVERMOLDING CONTINUOUS CARBON FIBER

Material: ±45°Fiberglass Biaxial Sleeving (12.8 oz/yd2) + Epikote RIMH135 + RIMR137 Hardener

“I NEVER KNEW THAT THERE WERE SO MANY DIFFERENT TYPES OF COMPOSITES AND SO MANY DIFFERENT WAYS TO MANUFACTURE THEM”

QC Evaluation of Filament Wound Tanks

INFUSION OF BRAIDED COMPOSITES for CNG TANKS

0.50

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1.49

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3

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7

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9

Ulti

mat

e Te

nsile

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engt

h, k

si

ASTM D412 Tensile Results

A: Neat Elvax 265 (UTS taken at 100% strain) B: Elvax 265 + Uni Carbon (2.57% by weight) C: Elvax 265 + Carbon ±45° Braid (7.88% by weight)

Compression Molding of Elvax 265 with Carbon Fiber Inserts

SURROGATE PREPREG PANEL FABRICATION

FUTURE WORK: INFUSE CARBON BRAID, PERFORM QC

Benchtop Filament WinderFUTURE WORK: • DRY WIND FLAT PANELS• RESIN FILMING• PANEL CONSOLIDATION• QC, MECHANICAL PROPERTIES

27IACMI Overview

Composite Materials & Processing Technology Area

Brayden AllerVanderbilt UniversityBachelor of Engineering Civil Engineering

Hosted By:Vanderbilt University

28IACMI Overview

29IACMI Overview


Mary DaffronUniversity of TennesseeBS Mechanical Engineering

Hosted By:Oak Ridge National Lab (ORNL)

THE DEVELOPMENT OF COST EFFECTIVE METHODS TO CREATE CONTINUOUS CARBON FIBER PREFORMS UTILIZING ADVANCED ROBOTICS

2016, Mary Daffron, The University of Tennessee, Sophomore, BS Mechanical EngineeringRobert Norris and Fue Xiong, Oak Ridge National Laboratory

BACKGROUND / OBJECTIVES PRELIMINARY RESULTS


• The Programmable Powdered PreformProcess (P4) has been used to createcarbon fiber preforms using choppedcarbon fiber.

• The discontinuous fiber preforms are madeup of randomly aligned fiber sections.

• The focus of this work is to develop amethod of creating a carbon fiber preformthat is both continuous and aligned utilizingthe P4 robot in order to compare itsproperties with those of a chopped carbonfiber preform.

MATERIALS AND METHODS• The P4 robot has been adapted to dispense carbon fiber tows

continuously by increasing the size of the carbon fiber sections and ultimately removing the blades

• The P4 robot has been changed to dispensed aligned, continuous fibers by modifying the programming to decrease the rate of fiber deposition

• Continuous, aligned carbon fiber preforms have been created utilizing the fibers laid by the P4 robot and compression molding

Chopped Carbon Fiber Preform

Fibers have been laid out by the P4 robot in a continuous and mostly aligned manner. They were then subjected to compression molding using a two part epoxy/resin system.

Continuous carbon fiber layers after deposition

completed

First two layers of continuous carbon fiber

deposited

• Mechanical testing to compare with chopped carbon fiber preforms (July – August)

• Improve the effects of the epoxy/resin system by finding the optimum fiber/resin ratio (July – August)

• Continue to improve fiber alignment by developing devices and processes to assist the robot in better tensioning and holding the deposited fibers in place (August – Future)

• Increase the speed of continuous fiber preform production (Future)

First compression molded preform after removal from the mold. Plans are to test panel, although matrix wet-out is incomplete and can be easily improved.

31IACMI Overview

Composite Materials & Processing Technology AreaHannah MaeserClemson UniversityBS Materials Science and EngineeringPolymer Concentration

Hosted By:University of Tennessee

Mechanical Properties of Pultruded Carbon Fiber CompositesMs. Hannah Maeser, 2016 Undergraduate Intern from CLEMSON UNIVERSITY, Research Mentors: Professor Dayakar Penumadu & Dr. Stephen Young, Materials and Processing,

IACMI, and University of Tennessee, KnoxvilleBACKGROUND / OBJECTIVES EXAMPLE RESULTS


• Increasing need for lighter and stronger materials atlow cost for wind, automotive, and infrastructuresectors demands research into low cost carbonfiber and its mechanical properties and rapidcomposite manufacturing methods

• Pultrusion is a low cost and high volumemanufacturing process

• This poster reports results from a novelcharacterization technique for obtaining spatiallyresolved strain data in tension for high volumefraction carbon fiber composite

MATERIALS AND METHODS• Unidirectional pultruded carbon fiber tows prepared to

ASTM standards for 0° unidirectional composites• Samples tabbed with 0.0625 in (1.5875 mm) thick G10

fiberglass tabs • Black speckle pattern was made on painted white

samples for VIC-3DTM imaging • Reflective tape placed on sample for laser-based

extensometer reading• Samples tested in 22 kip (98 kN) MTS universal testing

machine at 2mm/min displacement ramp and with 1 ksi(7 MPa) of grip pressure

• Pultruded samples demonstrated a tensile modulus of 160 GPa, tensile strength of 2 GPa at a failure strain of 1.2%.

June 2016 July 2016 August 2016Familiarization with standard characterization techniques with an understanding of IACMI mission

Mechanicaltesting of pultruded samples for tension, compression

10° off axis shear testing, preparationof report, draft technical paper for future submission

Reference: ASTM D3039

VIC-3DTM

tension sample after failure

Tabbed tension samples before testing

Hydraulic grips and pultruded carbon fiber composite with a (a) Wheatstone bridge and (b) laser based extensometer

Hydraulic grips and sample after failure

0

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Tensile Strain (VIC-3DTM)

A2 Poisson's Ratio DataSample A2 VIC-3DTM

tensile strain analysis

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ss (G

Pa)

Strain (mm/mm)

Sets A and B Stress-Strain Curve, failure

A2 B2

A1 B1

y = 160.65x - 0.0051R² = 0.9997

Modulus: 160.7 GPa

y = 158.88x - 0.0004R² = 1

Modulus: 158.9 GPa

0

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ss (G

Pa)

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Set A Stress-Strain Curve, to 3000 Microstrain

A2

A3 Wheatstone

A3 Laser

Linear (A2)

Linear (A3 Wheatstone)

b

0.5 in

a

10 in

Comparison of data using digital image correlation methods (VIC-3DTM), Wheatstone bridge, and laser-based extensometer

33IACMI Overview


Vikas PatelUniversity of Alabama BirminghamPhD Materials Science and Engineering

Hosted By:Oak Ridge National Lab (ORNL)

Carbon Fiber Recycling: Reincorporation of RecycledCarbon Fibers in New Composite Systems

2016, Vikas Patel1,2, Graduate StudentMentors: Dr. Soydan Ozcan1 and Dr. Halil L. Tekinalp1

1 Oak Ridge National Laboratory2University of Alabama at Birmingham

Background/Objective Results

Future Work

• Carbon fiber reinforced polymers (CFRPs) are being increasingly used by aerospace, automotive and other industries. Carbon fiber usage is projected to increase to ~130,000 Kilotons by 2020[1]. The increasing use generates an increasing amount of CFRP waste.

• Composite waste from end-of-life products and production scraps are being disposed in landfills, which is not the most favorable disposal route because of the negative environmental impact.

• Carbon fibers can be recovered from composite waste by different approaches such as pyrolysis or solvolysis. Energy to recover carbon fiber is only ~1/10th of the energy necessary to produce virgin carbon fiber[2].

• It is important to determine how recycled carbon fibers (rCFs) can be utilized in composite applications without significant loss in mechanical properties.

• In this work virgin unsized carbon fibers were used to produce composite systems with different carbon fiber loadings to emulate the use of rCFs in short-fiber reinforced thermoplastic composites.

Acrylonitrile-butadiene-styrene (ABS) co-polymer (GP35-ABS-NT) and unsized chopped Hexcel cabon fibers of 3.2 mm length were compounded with a Brabender Intelli-Torque Plasti-Corder prep-mixer at 220° C and 60 rpm rotor speed until the torque reading became constant. Mixtures of 10, 20, 30, and 40 wt% CFs were prepared. Neat ABS were also processed at the same conditions.

The composites and neat ABS were extruded and compression molded into testing bars, out of which dog-bones were cut using a Tensilkut template and a router based on ASTM D638 type-V dimensions.

Tensile properties were measured using a MTS machine at a strain rate of 0.0254 mm/s. A 10 mm gage-length extensometer was used for strain measurements.

Tensile properties of the composites made in this experiments with unsized carbon fibers are compared to the data obtained from literature of the same composite made with sized carbon fibers. The unsized fiber composites have favorable tensile properties compared to sized fiber composites. The tensile strength of the unsized carbon fiber composites reached the maximum value (87 MPa) at 20% fiber loading.

References

Fig. 1. CFRP recycling cycle. (a) CFRP waste from manufacturing scrap (top) end-of-life aircraft wing (bottom) (b) recovered rCFs (c) composite part produced using rCFs

Experimental

PyrolysisSolvolysis

Re-manufacturing

a

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)

Unsized CF

Sized CF

Fig. 2. Elastic Modulus and Tensile Strength of composites made with unsized carbon fibers in comparison to composites made with sized carbon fibers[3] (properties are a

average of data for at least 5 samples)

The same study is going to be performed with recycled carbon fibers. The properties are expected to be similar to the composite made with virgin unsized carbon fibers.

Fiber alignment studies are will be performed. Scanning electron microscopy (SEM) analysis of the fracture surface on tested samples

will be carried out in order to access fiber/matrix adhesion. Interfacial shear strength will be determined to quantify properties of the fiber matrix interface.

[1] Onishi M. 2012. Toray’s Business Strategy for Carbon Fiber Composite Materials. Toray Industries Inc.[2] Suzuki T, Takahashi J. 2005. Prediction of energy intensity of carbon fiber reinforced plastics for mass produced passenger cars. 9th Japan International SAMPE Symposium.[3] H.L. Tekinalp et al. 2014. Highly oriented carbon fiber-polymer composites via additive manufacturing. Composites Science and Technology;105:144-150.

This internship opportunity has given me beneficial knowledge and hands-on experience on composites manufacturing. Thank you IACMI and ORNL for this great opportunity.

Acknowledgments

35IACMI Overview


Jimmy BrayUniversity of Tennessee Masters in Mechanical Engineering

Hosted By:University of Tennessee College of Engineering

PERMEABILITY AND CHARACTERIZATION OF WOVEN AND NON CRIMPED FABRICSShailesh Alwekar, Jimmy Bray, University of Tennessee, Knoxville. Graduate Students

Mentor: Dr. Uday Vaidya

OBJECTIVES PERMEABILITY SET UP & CALCULATIONSBACKGROUNDVARTM and HP-RTM are liquid moldingprocesses for fast curing composites. These arecommonly used due to low tooling cost & easeof use. One of the important factor affects onthe manufacturability of composite parts ispermeability. Permeability usually affects theresin flow within fibers. Hencemanufacturers/OEMs need accuratepermeability to model and optimize themanufacturing processes.

• Conduct shear testing on wovencarbon fabric mat using pictureframe setup

• Measure bending length, flexuralrigidity

• Measure the permeability K1 & K2of carbon fabrics of plain, twilland satin weave architecture fordifferent mold openings

FABRIC CHARACTERIZATION

Bending stiffness setupPicture frame setup

FABRIC BENDING EQUATIONS• Bending length (C) = Overhang length ∗ 𝑓𝑓 𝜃𝜃

• 𝑓𝑓 𝜃𝜃 =𝑐𝑐𝑐𝑐𝑐𝑐 𝜃𝜃

28∗𝑇𝑇𝑇𝑇𝑇𝑇𝜃𝜃

13

• Flexural rigidity (G) = 9.809 × 10−6 ∗ 𝑀𝑀𝐶𝐶3where M = Fabric mass per unit area ( Kg/𝑚𝑚2)

Permeability setup

• Carbon fabric has higher bendlength as well as higher stiffnessthan textile fabric, glass fabricetc.

• Twill weave carbon fabric mathas more stiffness than satinweave carbon fabric mat

Flow front of resin after time “t”

KEY FINDINGS• Permeability changes with the mold opening, as mold opening

increases permeability of fiber mat increases• Permeability K1 ( flow direction llel to 0o fiber orientation) is always

grater than the K2 (flow direction perpendicular to 0o fiberorientation)

• As viscosity increases, permeability value decreases• OEMs need this data from a range of fabrics to produce reliable

parts in HP- RTM, VARTM & other liquid molding processes

y = 52.4x + 83.876R² = 0.9978

0

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L^2

(mm

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Graph of L2 vs t with mold opening 1.98 mm for K2

Series1 series 2

Linear (series 2)

y = 163.53x + 126.17R² = 0.999

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Graph of L2 vs t with mold opening 1.98 mm for K1

Series1 series 2

Linear (series 2)

• Empirical formula derived from Darcy’s Law

𝐾𝐾 =L2∗ɸ∗μ2∗t∗ΔP

where L=length of flow front, ΔP =pressure difference, t = mold fill time, ɸ = porosity of fibers, K = permeability of fibers

• Viscosity of Fluid µ = 𝑘𝑘𝑘𝑘 𝑝𝑝𝑓𝑓 − 𝑝𝑝Where k = viscometer constant, t = time of decent,𝑝𝑝𝑓𝑓= density of ball & 𝑝𝑝 = density of fluid

37IACMI Overview


Hicham GhosseinUniversity of Alabama BirminghamPhD Candidate Materials Science and Engineering

Hosted By:University of Tennessee College of Engineering

Advances in Wet –Laid Nonwoven Carbon Fiber Mats for Automotive ApplicationsHicham Ghossein (PhD student), Department of Materials Science and Engineering UAB & visiting Scholar at UTJames Brackett (Junior), Department of Materials Science and Engineering UTCody Knight (Freshman), Department of Mechanical, Aerospace & Biomedical Engineering, UTDavid McConnell (MS Student), Department of Mechanical, Aerospace & Biomedical Engineering, UT

BACKGROUND PRELIMINARY RESULTS


Wet laid (WL) process is adopted fornon-woven fiber reinforced polymermatrix composites mats, due to:• High productivity• Homogeneous thin material• Variable fiber orientation• Use of recycled fibers• Use of fiber blends• Low cost of production• Fiber length retention

MATERIALS AND METHODS Carbon fiber was dispersed in water using two different mixing methods. Experiment was established for pure carbon fiber mats as well as hybrid mats

of CF/Thermoplastics

September 2016 October 2017 December 2017

Mechanical testing & characterization of CF/Thermoplastic mats

Publication exploring simulation model of CF dispersion in water

Exploring mass scaleproduction of mats using the innovated mixing method

• Fathi-Khalfbadam et al. 2011. Analysis and simulation of fiber dispersion in water. J. of Dispersion Science and Technology 32:352–358

• Jayachandran, A. (2001, 08 13). Fundamentals of Fiber Dispersion in Water. Raleigh, North Carolina , USA• Akonda, M.H., C.A. Lawrence, and B.M. Weager, Recycled carbon fibre-reinforced polypropylene thermoplastic

composites. Composites Part A: Applied Science and Manufacturing, 2012. 43(1): p. 79-86.

OBJECTIVESResearch conducted at MDF aim to:• Optimization of non-woven WL

Mats for end-user productsapplication

• Analyze mechanical properties,fiber length retention and weightfraction for the process

• Develop a cost property processcycle model to achieve large scalesetup to cater medium volumeparts produced in automotiveindustry

iacmi student intern teams presentation

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