MDA/CERF: Durability Study Fatigue Task Group John J. Lesko Kenneth L. Reifsnider Stephan P. Phifer Charles E. Bakis Anthony Nanni Clem Heil ASME 2000

MDA/CERF: Durability StudyFatigue Task Group

John J. LeskoKenneth L. Reifsnider

Stephan P. PhiferCharles E. BakisAnthony Nanni

Clem Heil

ASME 2000 International Mechanical Engineering Congress & Exposition, November 2000

Fatigue Issue Not Covered in This Talk

?

Fatigue Failure Mechanisms

Fatigue-Life Diagram proposed by Talreja

Fatigue - Overview

•Failure Mechanisms

•Fiber

•Matrix

•Residual Cure Stress

•Interface - Sizing

•Laminate

•Processing

Material & Processing Effects

•Frequency/Creep

•Hygrothermal •Temperature

•Acid/Base/Electrolyte

Environmental & Testing Effects

Interactive Effects

Material Effects• Fatigue Failure Mechanisms

• Fiber

•E-glass, carbon/graphite, Kevlar

•Matrix

•Brittle, toughened

• Interface

•Compatible and non-compatible sizings

• Laminate

•Woven, stitched, and unidirectional

•Stacking sequence - 0°, ±45 °, 90° plies

• Processing Type

FIBERS - (0/90°)s

• Gathercole, Reiter,Adam, Harris 1994, IJ of Fatigue, v. 16, no. 8, p.523.

FIBERS - Tensile Stress Fatigue E-Glass

• Demers, Cornelia. E. 1997 The National Seminar on Advanced Composite Material Bridges, May 5-7.

0

10

20

30

40

50

60

70

80

90

100

1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 1.0E+08

# cycles

% U

ltim

ate

Tens

ile S

treng

th

Dry

Salt

Wet

run out

1 decade

11% UTS

Normalized Fatigue Performance of Glass/Vinyl Ester

F. McBagonluri, K. Garcia, M. Hayes, N. Verghese, & J. J. Lesko, "Characterization of Fatigue and Combined Environment on Durability Performance of Glass/Vinyl Ester Composite for Infrastructure Applications" International Journal of Fatigue, Vol. 22, Issue 1, 2000, pp. 53-64.

Glass Composite Fatigue1. Unidirectional glass/epoxy,

vf=0.52. Unidirectional glass/epoxy,

vf=0.333. Unidirectional glass/epoxy,

vf=0.164. 0°/90° glass5. 30-40% glass in

poly(hexamethylene adipamide), injection molded

6. 30-40% glass in polycarbonate injection molded

7. 30-40% glass in polyphenylenesulfide injection molded

8. 30-40% glass in poly(amide-imide) injection molded

9. Chopped-strand mat polyester10. Sheet molding compound

(smc) of rubber-modified epoxy

11. SMC, rubber-modified epoxy12. SMC, r5013. 0°/±45 ° /90° glass/epoxy14. Chopped-strand mat

polyester

Mandell, J. F., 1978, “Fatigue Behavior of Fibre-Resin Composites,” Developments in Reinforced Plastics 2, Properties of Laminates, Ed. G. Pritchard.

0200400600800

10001200140016001800

0 50 100 150

Slope S-N (MPa/Decade)

Str

engt

h (M

Pa)

Mandell's

As-received Extren

Aged Extren (Water)

Aged Extren (Salt)

UTS/B =10.7

Mechanism: Fatigue of Glass Composites

• Crack growth in the fiber dominates the failure process

• Accumulation of damage is accounted for in crack growth that takes place based on the fractional time spent at a damaging stress level

NIAK

dt

da aYKI

2N

1Nt

0 ultult

r dt)t(

C1

Glass fiber remaining strength given a (t)

Fatigue Simulation & Experiment

UCFR - unidirectional continuous fiber/epoxy

UCMFR - unidirectional & continuous strand mat fiber/vinyl ester

S-N Slope (%UTS/decade)Data: 10.2 and 13 Predictions: 12 to 14

0

0.2

0.4

0.6

0.8

1

1.2

1.E+00 1.E+02 1.E+04 1.E+06 1.E+08

# cycles

App

lied

Stre

ss/U

TS

UCFR10 Hz (Model)5 Hz (Model)2 Hz (Model)UCMFR

F. McBagonluri, G. Foster, S. Case, W. Curtin, & J. Lesko, “ Simulation Of Fatigue Performance Of Polymeric Composites For Infrastructure Applications,” Simulation of Fatigue Performance of Polymeric Composites for Infrastructure Applications ASME IMECE 98, Anaheim CA, Nov 1998

Matrix & Sizing Effects

Matrix Effects - S-N Curves for E-glass Laminates

• Konur & Matthews 1989, Composites, V.20, No. 4, July 1989.

Sizing & Matrix Toughening Effects

• Salvia, Fiore, Fournier & Vincent I.J. of Fatigue, 1997,V.19 No.3, p. 253.

BNA

NBA

oo

10

10max

log

log

Sizing Effects•EP - Epoxy Sizing

•MP - Multi-pupose sizing

•Epoxy Resin


10max logNBA

Pultruded AS-4/Derakane 411-35 LI: Sizing Effect

0

50

100

150

200

250

100 1000 10000 100000 1000000 10000000Number of Cycles

Phenoxy Sizing

G' Sizing

Run out

Input: R=0.1 Unidirectional Fatigue Data

Processing Effects

Process Type Effects

•FW - Filament Winding

•PMC - Prepreg Press Molding

•P - Pultrusion

• Salvia, Fiore, Fournier

& Vincent I.J. of Fatigue, 1997,V.19 No.3, p. 253.

BNAoo 10log

Process & Laminate Effects - Pultruded CP, Prepreg CP & Woven

0

0.2

0.4

0.6

0.8

1

1.E+03 1.E+04 1.E+05 1.E+06 1.E+07Fatigue Cycles (N)

No

rmal

ized

Lam

inat

e T

ensi

le

Fat

igu

e S

tres

s

Pultrude (0/90°)5T Vinyl Ester

Pultrude (0/90°)3S Vinyl Ester

Mandell (0/90°)S Epoxy

Adams (0/90°)S Epoxy

Mandell Epoxy 181 Woven

• Phifer 1998, Thesis Virginia Tech. http://scholar.lib.vt.edu/theses/available/etd-013199-185939

Laminated

Stitched or Woven

http://scholar.lib.vt.edu/theses/available/etd-013199-185939







Testing & Environmental Effects

•Testing•Mean Stress & R - Ratio

•Frequency

•Environmental•Hygrothermal

•Temperature

•pH Effects

Frequency & Mean Stress

Effects

Static vs. Dynamic Fatigue

•Mandell & Meier 1983 ASTM STP 813 p.60

• Gathercole, Reiter, Adam, Harris 1994, IJ of Fatigue, v. 16, no. 8, p.523.

Test Effects: R - ratio


• Adams, Fernando, Dickson, Reiter & Harris. 1989, IJ of Fatigue, V. 11, no. 4, p.233.

Environmental Effects

0

5000

10000

15000

20000

25000

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

# cycles

Str

ess

Leve

ls (p

si)

Dry

Wet

Salt

Sult dry= 30.7 ksiSult wet (water) = 22.9 ksiSult, wet (NaCl) = 20.9 ksi

R = 0.1freq = 10 Hz

run outs

Enviro-mechanical Fatigue of Glass/Vinyl

Ester

F. McBagonluri, K. Garcia, M. Hayes, N. Verghese, & J. J. Lesko, "Characterization of Fatigue and Combined Environment on Durability Performance of Glass/Vinyl Ester Composite for Infrastructure Applications" International Journal of Fatigue, Vol. 22, Issue 1, 2000, pp. 53-64.

Temperature Effects - S-N

Curves

• Branco, Ferreira, Fael & Richardson 1995 Int. J. Fatigue, V. 18, No. 4, p. 255

Effect of Temperature Effect on E-Glass FRP Fatigue

0

10

20

30

40

50

60

70

80

90

100

100 1,000 10,000 100,000 1,000,000 10,000,000

# cycles

% U

ltim

ate

Te

ns

ile S

tre

ng

th

0

5000

10000

15000

20000

Ma

x s

tre

ss

(p

si)

Sult = 20.9 ksi

R = 0.1freq = 10 Hz

65 °C30 °C

4 °C

Pultruded E-Glass/Vinyl Ester

So Where Are the Gaps?

•Combined Conditions•Creep & Fatigue

•Temperature & Fatigue

•Temp, Moisture & Fatigue

•Chemistry & Fatigue

•Spectrum loadings (stress and environment)

•Tools•Generalization of Glass Fatigue

•Remaining strength representations for combined loading

Estimating Remaining Strength

Life

Str

ess

or

Str

eng

th

NStress on Critical Element

Remaining Strength

Initia

l Stre

ngth

•Cycle dependent damage

•Kinetic

•Chemical

•Thermodynamic

Degradation Processes

GeometryConstitutive

Reifsnider & Stinchcomb, “A Critical Element Model of the Residual Strength and Life of Fatigue-loaded Composite Coupons,” ASTM STP 907, 1986

AMERICAN SOCIETY FOR COMPOSITES

16th Annual Technical Conference

CALL FOR PAPERS

September 9-12, 2001 Virginia Tech, Blacksburg, VA Donaldson Brown Hotel & Conference Center

http://www.esm.vt.edu/ASC/

Abstracts should be submitted no later than January 31, 2001.

M.W. Hyer by e-mail as a pdf file to [email protected]

mailto:[email protected]




QUESTIONS

Ranking of Importance of Data for Fatigue Effects

Application Area SustainedStress

Loading

Pure FatigueLoading

FatigueAnd Temp.

Fatigue &Moisture /

Salt

Fatigue &Creep

A B C A B C A B C A B C A B CInternal ReinforcementRebar 4 4 2 4 4 2 5 5 1 5 5 1 5 5 1External ReinforcementBeams 3 3 1 4 4 3 5 5 1 5 5 1 5 5 1Slabs 3 3 1 4 4 3 5 5 1 5 5 1 5 5 1Columns 4 4 1 4 4 1 5 5 1 5 5 1 5 5 1Seismic RetrofitColumns, piers 3 5 3 4 4 3 3 5 1 3 5 1 3 5 1Shear Walls 3 5 3 3 4 2 3 5 1 3 5 1 3 5 1Deck SystemsConventionalbeams/girders

4 4 1 5 5 1 5 5 1 5 5 1 5 5 1

Integral/compositebeams/girders

4 5 1 4 5 1 5 5 1 5 5 1 5 5 1

Structural ElementsWall panels, profiles 3 5 2 5 5 2 5 5 1 5 5 1 5 5 1

Rank 5: Critical, cannot go forward without it 3: Important 1: Good to have

Key: A composite B composite/substrate interface; adhesive (if any) C substrate

Ranking of Availability of Data for Fatigue Effects



Loading (1)

Pure FatigueLoading (2)

FatigueAnd

Temp.(3)

Fatigue &Moisture /

Salt (4)

Fatigue &Creep (5)


2 5 2 4 5 5 1 5 5 1 5 5 1


2 4 2 4 5 5 1 5 5 1 5 5 1


Rank 1: Widely available and validated3: Sparse and/or questionable5: Not available

Overall Ranking of Gaps for Fatigue Effects

Rank 2: Widely available and validated6: Sparse and/or questionable10: Not available



Loading

Pure FatigueLoading

FatigueAnd Temp.

Fatigue &Moisture /

Salt

Fatigue &Creep


6 9 9 9 10 10 2 10 10 2 10 10 2


6 9 6 9 10 10 2 10 10 2 10 10 2


MRLife Methodology1

“n”FatigueCycles

Damage Accumulation Increase in n) CLT

)(

)( Fa

0

00 qsX

n

T

)(

)(

0

00 qsXt

nXtFr

N

nJ

N

nd

N

nJnFaFrnFr

0

1000 )()()(1)0()(

Fa0°

Fr0°1

n2n1

Fa0°

1

N1N2

Off-AxisStiffness

Reductionn/N

Quasi-staticStrength & Stiffness

S-N

0° Critical 90° Subcritical

Fiber Effects

0

0.2

0.4

0.6

0.8

1

1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

Fatigue Cycles (N)

No

rma

lize

d T

en

sil

e F

ati

gu

e

Str

es

s

High Mod. Graphite

Low Mod. GraphiteKevlar

Uni- E-Glass181 Woven E-Glass

Mandell, J. F. 1982

• Jones, Dickson, Adam, Reiter, Harris 1983, Composites, V. 14, No.3, July

Material Effects - Kevlar Fibers - (0/90°)

KFRP

• Jones, Dickson, Adam, Reiter, Harris 1983, Composites, V. 14, No.3, July

Material Effects - E-Glass Fibers - (0/90°)

GRP

•Gathercole, Reiter,Adam, Harris 1994, IJ of Fatigue, v. 16, no. 8, p.523.

Material Effects - Carbon Fibers - (0/90°)

CFRP

Tensile Fatigue Damage Mechanism

• Kim & Ebert 1978, J. of Composite Matl., V. 12, April .

Manufacturing Effects

•S-N curves are dependent upon manufacturing process( P-pultrusion, FW-Filament Winding, PMC-Press Molding of Prepreg)

•Variations in resin and fiber sizing. Curve fit to

o & log(N10)o process related10max logNBA

BNAoo 10log


•Salvia, Fiore, Fournier & Vincent I.J. of Fatigue, 1997,V.19 No.3, p. 253.

BNA

NBA

oo

10

10max

log

log

Sizing Effects•EP - Epoxy Sizing

•MP - Multi-pupose sizing

•Epoxy Resin


10max logNBA

Process Effects

•FW - Filament Winding

•PMC - Prepreg Press Molding

•P - Pultrusion

• Salvia, Fiore, Fournier

& Vincent I.J. of Fatigue, 1997,V.19 No.3, p. 253.

BNAoo 10log


•Salvia, Fiore, Fournier & Vincent I.J. of Fatigue, 1997,V.19 No.3, p. 253.

Summary from Salvia et al.

•Pultrusion yields lower durabilility composites than Filament wound or press molded

•Resin and sizing strongly affect both A and B of

o was directly related to accoustic emission threshold. o(pultrusion) = 0.0

10max logNBA

Tensile Strain Fatigue

•Harris 1977 Composites Oct. p. 214.

Tensile Stress Fatigue

•Harris 1977 Composites Oct. p. 214.

Material Effects - Shear Fatigue - Mean Stress

•Bevan 1977 Composites Oct. p. 277.

Fatigue Failure Mechanims - Fatigue Stiffness Loss/Crack Development

• Jamison etc. 1984 ASTM STP 836 p38

Fatigue - Failure Mechanisms


Fatigue - Fiber Type


E-glass Type I Carbon

Type II Carbon

Fatigue - Fiber Type


Type III Carbon

Environmental Effects-Frequency

• Mandell & Meier 1983 ASTM STP 813 p.60

Environmental Effects- Dynamic Fatigue

• Mandell & McGarry 1985 Polymer Composites Vol. 6 No. 3 p.168

Single Fiber - NoFiber Interaction

Fiber Bundle

Environmental Effects- R ratio

• Mandell & Meier 1983 ASTM STP 813 p.60

Environmental Effects-Temperature

• Ma, Lin, Tai, Wu & Wu 1995, Polymer Composites, V.16, No.3, June.

Environmental Effects-Hygrothermal Aging

Pooled Fatigue data

• Ma, Lin, Tai, Wu & Wu 1995, Polymer Composites, V.16, No.3, June.

Environmental Effects R - ratio




)]101ln(1/[)/1(1

/

/

/

)])(1/[(

logNBAo

tc

tm

ta

fe

ef

c

m

a

mcmaf

where

e = endurance value of “f” at high Nfo = f value at low NA and B are curve fit constants needed for the wider range of R curves










• Schutz & Gerjarz 1977, Composites Oct. p. 245

• Schutz & Gerjarz 1977, Composites Oct. p. 245


• Highsmith & Reifsnider 1982, ASTM STP 775, p105.

FIBERS - Tensile Strain Fatigue

• Dharan 1975, J of Matl. Science, V.10, p. 1665.

Graphite

Matrix

E-glass




FIBERS - Shear Stress Fatigue (±45°) Fibers

FIBERS - Torsional Shear Strain Fatigue - Fiber/Resin

• Phillips & Scott 1977 Composites Oct. p. 233.

Material Effects - Sizing

• Shih & Ebert, 1987, Comp. Sci. & Tech., V.28, p.137.

Material Effects - Sizing

• Shih & Ebert, 1987, Comp. Sci. & Tech., V.28, p.137.



Process & Laminate Effects - Extracted Uni from Pultruded CP & QI Laminates vs. Uni

0

0.2

0.4

0.6

0.8

1

1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

Fatigue Cycles (N)

No

rmal

ized

Un

i- T

ensi

le

Fat

igu

e S

tres

s

CP2 CP1

QI1 QI2

QI2 at 45° Owen/Corn.

Demers Mandell

• Phifer 1998, Thesis Virginia Tech. http://scholar.lib.vt.edu/theses/available/etd-013199-185939








FIBERS - Tensile Stress Fatigue

• Dharan 1975, J of Matl. Science, V.10, p. 1665.

E-glass Graphite

• Adams, Dickson, etc. 1989, IJ of Fatigue, v. 11, no. 4, p.233.


Documents

MDA/CERF: Durability Study Fatigue Task Group John J. Lesko Kenneth L. Reifsnider Stephan P. Phifer Charles E. Bakis Anthony Nanni Clem Heil ASME 2000