Workshop on durability of composites in a marine environment

Durability of composite materials for underwater applications

Durability of composite materials for underwater applications

environment

23 – 24 August 2012

Nantes

Ifremer, France

Deep offshore exploitation

Lighter structures

Long term behavior

Specific propertiesBuoyancy, thermal insulation

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications 2

Oceanography

Long term behavior

Specific properties

Cost

EMR, Navy, …..

Deep sea marine environment

o Pressure

Parameters affecting long term durability

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications

o Temperature

o Chemical composition

o Biological activities

3

Deep sea marine environment

o Hydrostatic Pressure

In second level : P = 0.0101 z + 0.05 *10-6 z2 (to take into account water compressibility)

6000 metres = 62.5 MPa

in first approach 1 MPa every 100 meters

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications

P

(MPa)

Latitude (°)

0 30 45 60 90

5 497 496 495 495 494

10 992 991 989 988 987

20 1980 1977 1974 1972 1969

40 3941 3936 3930 3925 3920

60 5885 5877 5870 5862 5854

80 7813 7803 7792 7782 7772

100 9725 9713 9700 9687 9674

To be more precise depend on temperature, salinity, location …..

4

Deep sea marine environment

o Temperature around 4 °C from 1000 meters

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications 5

Deep sea marine environment

o Pressure

Parameters affecting long term durability

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications

o Temperature

o Chemical composition Oxygen content, Salinity

o Biological activities

6

Context – Previous study – Oceanography – Syntactic foams – Conclusions

5 Materials

4 Temperatures

2 Pressures

Durability of composite materials for underwater applications 7

2 Years

De ionized water

2.3 to 3.3 mm thick

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Difficult to reach saturation even at 60°C after 2 years

Globally no significant effect of pressure on water uptake

kinetics except for epoxy materials

PE VE EP1 EP2 PEEK

Durability of composite materials for underwater applications 8

.1MPa 10 Mpa .1MPa 10 Mpa .1MPa 10 Mpa .1MPa 10 Mpa .1MPa 10 Mpa

5°C 1.51 3.24 0.69 0.92 15 18.7 13.4 16.4 0.62 0.64

20°C 4.58 4.47 1.16 1.01 27.5 26.9 20.9 23.8 0.67 1.12

40°C 12.75 14.32 3.43 2.29 68.1 80 40.3 74.6 1 1.5

60°C 16.56 17.68 4.6 3.49 109 152.5 120.9 185.1 2.1 1.5

No effect of pressure on mechanical degradation pro cess

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications 9

20 years of experience on testing composite pressur e housings

Context – Previous study – Oceanography – Syntactic foams – Conclusions

1000

1500Im

plos

ion

pres

sure

, bar

s Cylinder failure modes

Max. Hoop stress

Buckling

Test data

BUCKLING

Durability of composite materials for underwater applications 10

0

500

-2,91E-1 0,02 0,04 0,06 0,08 0,1 0,12

Impl

osio

n pr

essu

re, b

ars

thickness/diameter

MATERIAL FAILURE

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Creep strains measured at sea, 2500 m depth (3 stra in gauges)12 mm thick glass/epoxy cylinder

4000

5000

6000

7000H

oop

mic

rost

rain

Durability of composite materials for underwater applications 11

0

1000

2000

3000

0 1000 2000 3000 4000Time, hours

Hoo

p m

icro

stra

in

Creep buckling occurrence ?

Context – Previous study – Oceanography – Syntactic foams – Conclusions

70

80

90

% o

f sta

tic fa

ilure

Very few fatigue data

Glass epoxy cylinders under hydrostatic pressure

Durability of composite materials for underwater applications 12

40

50

60

70

0 100 200 300 400 500 600

% o

f sta

tic fa

ilure

Nb of cycles

no failure

data from EUCLID program

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Introduction of long term behavior into a new standard for qualification of oceanographic

equipment

Instrumented test in order to extrapolate duration limit of qualification

Durability of composite materials for underwater applications 13

of qualification

Fatigue test : 10 cycles at Service Pressure

96 hours Creep test at 1.2 SP or 1.1SP(depending on class equipment)

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications

Adrien et al Acta Mat. 55-2007Adrien et al Acta Mat. 55-2007

14

10 to 100 µm ∅

1 to 2 µm thickness

Context – Previous study – Oceanography – Syntactic foams – Conclusions

15Durability of composite materials for underwater applications

Buoyancy application 6000 meters ρ =0.58 Glass epoxy syntactic foam

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications

Thermal insulation & Buoyancy application

Long term behavior (> 20 years) under high hydrostatic pressure and high thermal gradient (temperature up to 130 °C)

16

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Insulated pipe

Durability of composite materials for underwater applications 17

Glass syntactic polypropylene

Glass syntactic polyurethane

Glass epoxy syntactic foam

……..

Riser tower

Xmas tree

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite materials for underwater applications 18

Samples of different sizes

Pressure up to 30 Mpa

Temperature up to 160°C

Natural sea water

Up to 10 000 hours of ageing

Water uptake kinetics

Evolution of mechanics & thermal properties

Long term aging model

Context – Previous study – Oceanography – Syntactic foams – Conclusions

20

30

Wei

ght i

ncre

ase

(%)

40°C P atm40°C P 30 MPa80°C P atm80°C P 30 MPa

2 months 9 months

Durability of composite materials for underwater applications 19

0

10

0 5 10 15 20 25 30

t (h) 1/2 / h(mm)

Wei

ght i

ncre

ase

(%)

Temperature & Pressure coupling effect

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Water uptake modeling

Durability of composite material for underwater applications 20

GSPU 80°C – 14 months

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite material for underwater applications 21

Epoxy syntactic foam (Nautile)20 years

• Parameter’s determination: Creep tensile test on DMA

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Modeling of thermo-mechanical of GSPP

Durability of composite materials for underwater applications 22

25°C 40°C60°C 80°C

100°C

• Parameter’s determination: Creep tensile test on DMA

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Durability of composite material for underwater applications 23

Syntactic foam + macro ballon (∅ >10 cm)

Long term behaviour ???

Context – Previous study – Oceanography – Syntactic foams – Conclusions

Increasing demand for use of composite materials in the offshore

domain

Important on going experimental programs for developing, in

particular, deep sea composite risers

Generally low water temperature and important thickness of deep

sea structures will minimize the potential effect of water uptake

Durability of composite material for underwater applications 24

sea structures will minimize the potential effect of water uptake

Significant temperature-pressure coupling for syntactic foam

TO BE INVESTIGATED

Effect of higher pressure

Creep buckling under hydrostatic pressure

Long term behavior of buoyancy material with macro balloons

Durability of composite material for underwater applications 25

0 MPa

Durability of composite material for underwater applications 26

10 MPa

Durability of composite material for underwater applications 27

30 MPa

Durability of composite material for underwater applications 28

40 MPa

Durability of composite material for underwater applications 29

50 MPa

Durability of composite material for underwater applications 30

0 MpaAfter

loading

Durability of composite material for underwater applications 31

Thank you for

Durability of composite materials for underwater applications 32

your attention