Durability of composite materials for underwater applications
Workshop on durability of composites in a marine environment 23 – 24 August 2012 Nantes
Ifremer, France
Durability of composite materials for underwater applications Context – Previous study – Oceanography – Syntactic foams – Conclusions
Deep offshore exploitation
Lighter structures Long term behavior Specific properties Buoyancy, thermal insulation
Oceanography
Long term behavior Specific properties Cost
EMR, Navy, …..
Durability of composite materials for underwater applications 2 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Deep sea marine environment
Parameters affecting long term durability
o Pressure
o Chemical composition
o Biological activities
Durability of composite materials for underwater applications 3 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Deep sea marine environment
o Hydrostatic Pressure in first approach 1 MPa every 100 meters
In second level : P = 0.0101 z + 0.05 *10 -6 z2 (to take into account water compressibility) 6000 metres = 62.5 MPa
To be more precise depend on temperature, salinity, location …..
P Latitude ( °) 0 30 45 60 90 (MPa) 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
Durability of composite materials for underwater applications 4 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Deep sea marine environment
o Temperature around 4 °C from 1000 meters
Durability of composite materials for underwater applications 5 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Deep sea marine environment
Parameters affecting long term durability
o Pressure
o Temperature
o Chemical composition Oxygen content, Salinity
o Biological activities
Durability of composite materials for underwater applications 6 Context – Previous study – Oceanography – Syntactic foams – Conclusions
5 Materials
2 Years
De ionized water
2.3 to 3.3 mm thick
Durability of composite materials for underwater applications 7 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 .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 process
Durability of composite materials for underwater applications 8 Context – Previous study – Oceanography – Syntactic foams – Conclusions
20 years of experience on testing composite pressure housings
Durability of composite materials for underwater applications 9 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Cylinder failure modes 1500 BUCKLING
1000 Max. Hoop stress Buckling Test data
500 MATERIAL FAILURE Implosion pressure, barsbars pressure,pressure, ImplosionImplosion
0 -2,91E-1 0,02 0,04 0,06 0,08 0,1 0,12 thickness/diameter
Durability of composite materials for underwater applications 10 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Creep strains measured at sea, 2500 m depth (3 strain gauges) 12 mm thick glass/epoxy cylinder
7000
6000
5000
4000
3000 HoopHoopmicrostrain microstrain 2000
1000
0 0 1000 2000 3000 4000 Time, hours Creep buckling occurrence ?
Durability of composite materials for underwater applications 11 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Very few fatigue data
Glass epoxy cylinders under hydrostatic pressure 90
80
70
60 no failure % of static static static ofoffailure failure % % 50
40 0 100 200 300 400 500 600 Nb of cycles data from EUCLID program
Durability of composite materials for underwater applications 12 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
Fatigue test : 10 cycles at Service Pressure
96 hours Creep test at 1.2 SP or 1.1SP (depending on class equipment)
Durability of composite materials for underwater applications 13 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Adrien et al Acta Mat. 55-2007
10 to 100 µm ∅
1 to 2 µm thickness
Durability of composite materials for underwater applications 14 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Buoyancy application 6000 meters ρ =0.58 Glass epoxy syntactic foam
Durability of composite materials for underwater applications 15 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Thermal insulation & Buoyancy application
Long term behavior (> 20 years) under high hydrostatic pressure and high thermal gradient (temperature up to 130 °C)
Durability of composite materials for underwater applications 16 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Insulated pipe
Riser tower Glass syntactic polypropylene Glass syntactic polyurethane Glass epoxy syntactic foam Xmas tree ……..
Durability of composite materials for underwater applications 17 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Samples of different sizes Water uptake kinetics Pressure up to 30 Mpa Evolution of mechanics & thermal properties Temperature up to 160 °C Long term aging model Natural sea water Up to 10 000 hours of ageing
Durability of composite materials for underwater applications 18 Context – Previous study – Oceanography – Syntactic foams – Conclusions
30 40°C P atm 40°C P 30 MPa 80°C P atm 80°C P 30 MPa
20 2 months 9 months
10 Weight increaseincrease Weight Weight (%) (%)
0 0 5 10 15 20 25 30 t (h) 1/2 / h(mm)
Temperature & Pressure coupling effect
Durability of composite materials for underwater applications 19 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Water uptake modeling
Durability of composite material for underwater applications 20 Context – Previous study – Oceanography – Syntactic foams – Conclusions
GSPU 80°C – 14 months
Epoxy syntactic foam (Nautile) 20 years
Durability of composite material for underwater applications 21 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Modeling of thermo-mechanical of GSPP
• Parameter’s determination: Creep tensile test on DMA
100°C
60°C 80°C 40°C 25°C
Durability of composite materials for underwater applications 22 Context – Previous study – Oceanography – Syntactic foams – Conclusions
Syntactic foam + macro ballon (∅ >10 cm) Long term behaviour ???
Durability of composite material for underwater applications 23 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 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 24 0 MPa
Durability of composite material for underwater applications 25 10 MPa
Durability of composite material for underwater applications 26 30 MPa
Durability of composite material for underwater applications 27 40 MPa
Durability of composite material for underwater applications 28 50 MPa
Durability of composite material for underwater applications 29 0 Mpa After loading
Durability of composite material for underwater applications 30 Durability of composite material for underwater applications 31 Thank you for your attention
Durability of composite materials for underwater applications 32