Mechanical Characterization of Particulate Filled Vinyl-Ester Composite. Steven Taylor The University of Tulsa Under the direction of: Dr. Michael A. DeBolt, Ford Motor Company Dr. John M. Henshaw, the University of Tulsa. Overview. Introduction / Background Materials and Molding Process - PowerPoint PPT Presentation
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Mechanical Characterization Mechanical Characterization of Particulate Filled of Particulate Filled Vinyl-Ester Composite Vinyl-Ester Composite Steven Taylor Steven Taylor The University of Tulsa The University of Tulsa Under the direction of: Under the direction of: Dr. Michael A. DeBolt, Ford Motor Dr. Michael A. DeBolt, Ford Motor Company Company Dr. John M. Henshaw, the University of Dr. John M. Henshaw, the University of Tulsa Tulsa
Transcript
Mechanical Characterization of Mechanical Characterization of Particulate Filled Vinyl-Ester Particulate Filled Vinyl-Ester
CompositeComposite Steven TaylorSteven Taylor
The University of TulsaThe University of Tulsa
Under the direction of:Under the direction of:Dr. Michael A. DeBolt, Ford Motor CompanyDr. Michael A. DeBolt, Ford Motor CompanyDr. John M. Henshaw, the University of TulsaDr. John M. Henshaw, the University of Tulsa
Modeling and AnalysisModeling and Analysis– Theoretical ModelsTheoretical Models– Semi-Empirical ModelsSemi-Empirical Models– Finite Element AnalysisFinite Element Analysis
Testing ResultsTesting Results– Mechanical TestingMechanical Testing– Microstructure and Fracture Surface AnalysisMicrostructure and Fracture Surface Analysis
Summary and ConclusionsSummary and Conclusions
IntroductionIntroduction
Sheet Molding Compound (SMC)Sheet Molding Compound (SMC)– Used in a variety of applicationsUsed in a variety of applications– Automotive Industry Automotive Industry
Literature search on lightweight filled materialsLiterature search on lightweight filled materials
Models which predict material properties of filled Models which predict material properties of filled resin systemsresin systems
Tests and procedures used to qualify new materialsTests and procedures used to qualify new materials
Results and conclusions found in previous workResults and conclusions found in previous work
BackgroundBackground
Specific Properties and Fracture Toughness of Specific Properties and Fracture Toughness of Syntactic Foam: Effect of Foam MicrostructuresSyntactic Foam: Effect of Foam MicrostructuresWouterson, Boey, Hu, WongWouterson, Boey, Hu, Wong
– Epicote 1006 epoxy resin systemEpicote 1006 epoxy resin system
– 3M glass bubbles K 15 and K46 and Phenoset BJO-093 as filler3M glass bubbles K 15 and K46 and Phenoset BJO-093 as filler
– Mechanical test data were normalized and presented as specific Mechanical test data were normalized and presented as specific
mechanical and fracture propertiesmechanical and fracture properties
– An increase in specific tensile strength and decrease in flexural strength An increase in specific tensile strength and decrease in flexural strength with larger volume percentswith larger volume percents
– Plastic deformation of the epoxy and debonding of microspheresPlastic deformation of the epoxy and debonding of microspheres
BackgroundBackground
On the Modulus of Three-Component On the Modulus of Three-Component Particulate-Filled CompositesParticulate-Filled CompositesDickieDickie
– Glass beads and dispersed rubber as fillerGlass beads and dispersed rubber as filler
– Performed tensile test to determine the modulus of the materialPerformed tensile test to determine the modulus of the material
– Kerner model was an inappropriate fit for modulusKerner model was an inappropriate fit for modulus
– Modulus may be dependent on size distribution, filler particle Modulus may be dependent on size distribution, filler particle deformability and filler to matrix modulus ratiosdeformability and filler to matrix modulus ratios
BackgroundBackground
Elastic Modulus of Two-Phase MaterialsElastic Modulus of Two-Phase MaterialsHsieh, TuanHsieh, Tuan
– Aluminum oxide containing 0 to 100% volume percentage of nickel Aluminum oxide containing 0 to 100% volume percentage of nickel aluminidealuminide
– Compared 12 different theoretical models to experimental resultsCompared 12 different theoretical models to experimental results
– Reuss and Hashin-Shtrikman lower bond equations gave the best Reuss and Hashin-Shtrikman lower bond equations gave the best predications of modulus out of 12 modelspredications of modulus out of 12 models
Problem StatementProblem Statement
Compare lightweight filler to traditional filler in absence of Compare lightweight filler to traditional filler in absence of fiber reinforcementfiber reinforcement
Determine the ‘effective modulus’ of light weight fillerDetermine the ‘effective modulus’ of light weight filler
Find effects of incremental amount of filler on material Find effects of incremental amount of filler on material properties such as density, shrinkage, tensile and properties such as density, shrinkage, tensile and flexural strength, and thermal expansionflexural strength, and thermal expansion
Determine which material models most accurately Determine which material models most accurately predict material trends predict material trends
Materials and Materials and Molding ProcessMolding Process
Introduction & Background
Materials & Molding Process
Modeling & Analysis
TestingResults
Summary & Conclusions
Materials and Molding ProcessMaterials and Molding Process
Base ResinBase Resin– Ashland Arotech Q6055 resinAshland Arotech Q6055 resin– Luperox DDM-9 catalystLuperox DDM-9 catalyst– Westdry Cobalt 6% and Westdry Cobalt 6% and
Aldrich N, N-DimethylanilineAldrich N, N-Dimethylaniline
Materials and Molding ProcessMaterials and Molding Process
Molding ApparatusMolding Apparatus
1 Compressed Air Line
2 Pressure Pot
3 Resin Flow Valve
4 Resin Inlet Tube
5 Resin Inlet Tube Clamp
6 Mold Surface
7 Resin Out / Vacuum Tube
8 Resin Out Tube Clamp
9 Mold Heaters
4
6
1
3
8
2
5
7
9
Modeling and Modeling and AnalysisAnalysis
Introduction & Background
Materials & Molding Process
Modeling & Analysis
TestingResults
Summary & Conclusions
Material ModelingMaterial Modeling
Modeling to predict material propertiesModeling to predict material properties– Reduces costly experimentsReduces costly experiments– Allows faster development of new materialsAllows faster development of new materials
Theoretical and Empirical Models Theoretical and Empirical Models – Rule of MixturesRule of Mixtures
Parallel and SeriesParallel and Series– Reuss ModelReuss Model– Voigt ModelVoigt Model– Halphin-TsaiHalphin-Tsai– Hashin-Strikman BoundsHashin-Strikman Bounds– Kerner ModelKerner Model– Paul ModelPaul Model– Differenital Effective Medium TheoryDifferenital Effective Medium Theory
Finite Element Analysis (FEA)Finite Element Analysis (FEA)– ANSYS and ABAQUSANSYS and ABAQUS
Material Modeling ResultsMaterial Modeling Results
Paul, Kerner and Hashin-Strikman lower Bounds models Paul, Kerner and Hashin-Strikman lower Bounds models most accurately predicts the modulus of plaques most accurately predicts the modulus of plaques containing calcium carbonatecontaining calcium carbonate
Parallel model best fits density, tensile and flexural UTS, Parallel model best fits density, tensile and flexural UTS, and thermal expansion test dataand thermal expansion test data
Material ModelsMaterial Models
Finite Element AnalysisFinite Element AnalysisModeled one-quarter of the cross section Modeled one-quarter of the cross section
of a unit cell.of a unit cell.
Set the properties of the matrix equal that Set the properties of the matrix equal that of the vinyl-ester resinof the vinyl-ester resin
Created a thin walled shell and ‘glued’ the Created a thin walled shell and ‘glued’ the surfaces of the shell to the resinsurfaces of the shell to the resin
Substituted the hollow glass sphere of the Substituted the hollow glass sphere of the hollow sphere with a solid spherical hollow sphere with a solid spherical particle with unknown mechanical particle with unknown mechanical properties properties
Material ModelsMaterial ModelsFinite Element ResultsFinite Element Results
Control Stress Contour Plot Control Strain Contour Plot
Material ModelsMaterial ModelsFinite Element ResultsFinite Element Results
3M-S22 Axisymmetric Stress Contour Plot
2D Simplified Stress Contour Plot
Material ModelsMaterial ModelsFinite Element ResultsFinite Element Results
3M-S22 Axisymmetric Strain Contour Plot
2D Simplified Strain Contour Plot
Material ModelsMaterial ModelsFinite Element ResultsFinite Element Results
Glass Spheres will carry most of the load around Glass Spheres will carry most of the load around the air pocket with “perfect” bond strength.the air pocket with “perfect” bond strength.
The resin has the greatest strains at 45The resin has the greatest strains at 45° from ° from direction of applied load.direction of applied load.
High stress concentration for polymeric High stress concentration for polymeric microspheres.microspheres.
Unable to find an ‘effective’ modulus and Unable to find an ‘effective’ modulus and Poisson's ratio.Poisson's ratio.
Measured test plaques as molded than Measured test plaques as molded than took additional measurements after post took additional measurements after post curecure
Insignificant changes between as molded Insignificant changes between as molded and post cured resultsand post cured results
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
0% 10% 20% 30% 40% 50%
Filler Volume Percentage
Per
cen
t S
hri
nka
ge
Percent ShrinkagePercent Shrinkage
▲Neat Vinyl-Ester Resin
♦ Calcium Carbonate
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
0% 10% 20% 30% 40% 50%
Filler Volume Percentage
Per
cen
t S
hri
nka
ge
Percent ShrinkagePercent Shrinkage
▲Neat Vinyl-Ester Resin
♦ Calcium Carbonate■ 3M-S32 Hollow Glass Spheres
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
0% 10% 20% 30% 40% 50%
Filler Volume Percentage
Per
cen
t S
hri
nka
ge
Percent ShrinkagePercent Shrinkage
▲Neat Vinyl-Ester Resin
♦ Calcium Carbonate
♦ Hollow Polymeric Spheres
Percent ShrinkagePercent Shrinkage
Large amount of scatterLarge amount of scatter– Inaccurate measuring techniquesInaccurate measuring techniques
Decreasing trend in maximum percent Decreasing trend in maximum percent shrinkage with increase in volume shrinkage with increase in volume percentpercent
Insignificant changes between as molded Insignificant changes between as molded and post cured resultsand post cured results
Density Test ApparatusDensity Test Apparatus
Test performed per ASTM 792-00Test performed per ASTM 792-00
1. Weighing pan of Mettler Toledo balance
2. Bracket attached to weighing pan
3. Bracket to pan attachment screws
4. Beaker Bridge
5. 250ml Beaker
6. Sinker and test specimen
7. Sinker and test specimen holder
8. Thermometer
0.0
0.5
1.0
1.5
2.0
2.5
0% 10% 20% 30% 40% 50% 60%
Volume Percentage of Filler (%)
Den
sity
(g
/cm
3 )
DensityDensity
▲Neat Vinyl-Ester Resin
♦ Calcium Carbonate
♦ Polymeric Microspheres
Density Test ResultsDensity Test Results
Small amount of scatterSmall amount of scatter
Parallel model best predicted test resultsParallel model best predicted test results
– Linear Increase in density with increase in calcium Linear Increase in density with increase in calcium carbonatecarbonate
– Linear decrease in density with increase in Linear decrease in density with increase in leightweight fillerleightweight filler
Uni-axial Tensile Test ResultsUni-axial Tensile Test Results
Young’s ModulusYoung’s Modulus– Compared results with theoretical material models.Compared results with theoretical material models.
Ultimate Tensile StressUltimate Tensile Stress
Maximum Strain to FailureMaximum Strain to Failure
Testing performed in accordance with ASTM D638Testing performed in accordance with ASTM D638
80 mm
13 mm
20 mm
45 mm
3.3 mm12.7 mm 23 mm
0
2000
4000
6000
8000
10000
12000
14000
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Mo
du
lus
(MP
a)
Tensile Test ResultsTensile Test ResultsYoung’s ModulusYoung’s Modulus
▲Neat Vinyl-Ester Resin
♦ Calcium Carbonate
Parallel
Paul
Series
Hashin-Shtrikman
Kerner
0
2000
4000
6000
8000
10000
12000
14000
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Mo
du
lus
(Mp
a)
Tensile Test ResultsTensile Test ResultsYoung’s ModulusYoung’s Modulus
▲Neat Vinyl-Ester Resin
♦ Calcium Carbonate■ 3M-S32 Hollow Glass Spheres
Kerner
Paul
Hashin-ShtrikmanSeriesParallel
0
2000
4000
6000
8000
10000
12000
14000
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Mo
du
lus
(Mp
a)
Tensile Test ResultsTensile Test ResultsYoung’s ModulusYoung’s Modulus
▲ Neat Vinyl-Ester Resin
♦ Calcium Carbonate
♦ Polymeric Microspheres
Kerner
Paul
Hashin-ShtrikmanSeriesParallel
0
10
20
30
40
50
60
70
80
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Str
ess
(Mp
a)
Tensile Test ResultsTensile Test ResultsUltimate Tensile StrengthUltimate Tensile Strength
▲ Neat Vinyl-Ester Resin
♦ Calcium Carbonate
0
10
20
30
40
50
60
70
80
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Str
ess
(Mp
a)
0
10
20
30
40
50
60
70
80
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Str
ess
(Mp
a)
Tensile Test ResultsTensile Test ResultsUltimate Tensile StrengthUltimate Tensile Strength
▲ Neat Vinyl-Ester Resin
♦ Calcium Carbonate■ 3M-S32 Hollow Glass Spheres
0
10
20
30
40
50
60
70
80
0% 10% 20% 30% 40% 50%
Volume Percentage of Filler (%)
Str
ess
(Mp
a)
Tensile Test ResultsTensile Test ResultsUltimate Tensile StrengthUltimate Tensile Strength
▲ Neat Vinyl-Ester Resin
♦ Calcium Carbonate
♦ Polymeric Microspheres
Tensile Test ResultsTensile Test Results
Paul and Kerner model best predicts the modulus of palques Paul and Kerner model best predicts the modulus of palques containing calcium carbonatecontaining calcium carbonate
The ‘effective modulus’ of both the hollow glass and polymeric The ‘effective modulus’ of both the hollow glass and polymeric microspheres is equal to ~3450 Mpamicrospheres is equal to ~3450 Mpa
Ultimate tensile strength is independent of filler type and had a Ultimate tensile strength is independent of filler type and had a linear decrease with increased filler percentagelinear decrease with increased filler percentage
Decrease in maximum strain to failure with larger volume percents Decrease in maximum strain to failure with larger volume percents of fillerof filler
Insignificant differences between 4 different series of hollow glass Insignificant differences between 4 different series of hollow glass spheresspheres
Flexural Test ResultsFlexural Test ResultsFlexural ModulusFlexural Modulus
Flexural StrengthFlexural Strength
Maximum Flexural Strain to FailureMaximum Flexural Strain to Failure
Test performed in accordance to ASTM 6272- 02Test performed in accordance to ASTM 6272- 02
Specimen Size of 80mm X 13mm X 3mmSpecimen Size of 80mm X 13mm X 3mm
3
L
2
'P
P
3
L
2
'P
3
L
TEST SPECIMEN
Coefficient of Thermal ExpansionCoefficient of Thermal Expansion
Coefficient of Linear Thermal ExpansionCoefficient of Linear Thermal Expansion
– 3030°C to 150°C°C to 150°C
– Ramp 0.5°C / minRamp 0.5°C / min
– 50.0 mm rod of NIST standard fused silica 73950.0 mm rod of NIST standard fused silica 739
– Test Specimens 50 mm X 8 mm X 3 mmTest Specimens 50 mm X 8 mm X 3 mm
Thermal Expansion Test ResultsThermal Expansion Test Results
Model hollow glass particulate filler as solid Model hollow glass particulate filler as solid particulate filler with same value for thermal particulate filler with same value for thermal expansionexpansion
Parallel model does good job in predicting Parallel model does good job in predicting downward trend of test datadownward trend of test data
Microstructure AnalysisMicrostructure Analysis
Conducted microstructure analysis to see Conducted microstructure analysis to see distribution of spheres distribution of spheres Used Image-J software to get an Used Image-J software to get an approximate value of volume percent filler approximate value of volume percent filler for samples containing polymeric for samples containing polymeric micropsheresmicropsheresSEM images to determine failure modeSEM images to determine failure modeFracture surface of 40 percent filler for Fracture surface of 40 percent filler for each material.each material.
Lack of polymeric microspheres for all volume fractionsLack of polymeric microspheres for all volume fractions
Good distribution of calcium carbonateGood distribution of calcium carbonate
Hollow glass spheres are grouped together at lower Hollow glass spheres are grouped together at lower volume fractionsvolume fractions
Debonding between filler and matrixDebonding between filler and matrix
Small amounts of Plastic Yielding in resinSmall amounts of Plastic Yielding in resin
Introduction & Background
Materials & Molding Process
Modeling & Analysis
TestingResults
Summary & Conclusions
Summary andSummary andConclusionsConclusions
Summary and ConclusionsSummary and Conclusions
The elastic modulus of resin containing calcium carbonate is The elastic modulus of resin containing calcium carbonate is higher than the resin containing lightweight filler of equal higher than the resin containing lightweight filler of equal volume percentagesvolume percentages
The Paul theoretical model does best in fitting both the The Paul theoretical model does best in fitting both the calcium carbonate and hollow glass and polymeric calcium carbonate and hollow glass and polymeric microspheres data for elastic modulusmicrospheres data for elastic modulus
Insignificant differences between the 4 different series of 3M Insignificant differences between the 4 different series of 3M spheres for tensile, flexural and thermal expansion test dataspheres for tensile, flexural and thermal expansion test data
The effective modulus of the hollow glass and polymeric The effective modulus of the hollow glass and polymeric microspheres is equal to that of the vinyl ester with a value of microspheres is equal to that of the vinyl ester with a value of ~3450Mpa.~3450Mpa.
Summary and ConclusionsSummary and Conclusions
Adding filler to the vinyl ester creates a decrease in strength Adding filler to the vinyl ester creates a decrease in strength of the material, which is independent of filler type.of the material, which is independent of filler type.
The strains to failure of the materials filled with calcium The strains to failure of the materials filled with calcium carbonate are lower than those filled with the hollow glass and carbonate are lower than those filled with the hollow glass and polymeric microspheres with equal filler content.polymeric microspheres with equal filler content.
Scatter in percent shrinkage measurements may be caused Scatter in percent shrinkage measurements may be caused by inadequate measuring techniques.by inadequate measuring techniques.
Debonding of the resin from lightweight fillers and breakage of Debonding of the resin from lightweight fillers and breakage of the spheres was observed in the failed samples. the spheres was observed in the failed samples.
RecommendationsRecommendations
Further investigation should be performed to explain the Further investigation should be performed to explain the large amount of scatter in the percent shrinkage of plaques large amount of scatter in the percent shrinkage of plaques containing no filler. containing no filler.
Further testing should be performed to fully explain the Further testing should be performed to fully explain the lower than expected percentage of polymeric microspheres lower than expected percentage of polymeric microspheres in molded plaques for all volume fractions.in molded plaques for all volume fractions.
Sizing effects should be investigated to create a greater Sizing effects should be investigated to create a greater bond strength between filler and resin to increase the bond strength between filler and resin to increase the ultimate tensile strength of the material. ultimate tensile strength of the material.
Expand on finite element models of lightweight to Expand on finite element models of lightweight to incorporate bond strength, predict compressive effectsincorporate bond strength, predict compressive effects
