IFREMER-ONR Workshop « DURABILITY OF COMPOSITES IN A MARINE ENVIRONMENT » IN SERVICE EXPERIENCE IN SERVICE EXPERIENCE AT DCNS AT DCNS Frédérique LE LAY – DCNS Research – 24/08/2012
OVERVIEW ABOUT DCNS COMPOSITE STRUCTURES AT DCNS SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES IN SERVICE EXPERIENCE NATURAL AGEING / ACCELERATED AGEING CORRELATION CONCLUSION 2/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
ABOUT DCNS ABOUT DCNS
ABOUT DCNS AT A GLANCE A world leader in naval defence. An innovative player in energy. 3,2 billion 2,6 billion euros in order euros in intake revenue 1/3 of revenue 12 900 from int’l sales & employees cooperation programmes 2011 key figures 4/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
ABOUT DCNS Over 350 years’ experience in naval defence 10 sites in France International presence Five areas of expertise � Naval architecture � Engineering � Shipyard management and ship assembly and integration � Equipment design and production � Through-life support (TLS) 5/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
ABOUT DCNS Naval defence activities � Surface ships and naval systems � Submarines Energy activities � Civil nuclear engineering (CNE) � Marine renewable energies (MRE) 6/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
COMPOSITE STRUCTURES COMPOSITE STRUCTURES AT DCNS AT DCNS
COMPOSITE STRUCTURES AT DCNS MATERIALS & TECHNOLOGIES Materials : � Resins : polyester, vinylester, epoxy, phenolic � Fibers : glass, carbon, aramid � Sandwich core : balsa, synthetic foams, syntactic foam Production technologies : � Hand-lay up � Prepreg � Infusion � Others : RTM, pultrusion 8/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
COMPOSITE STRUCTURES AT DCNS SURFACE SHIPS Minesweepers (CMT) – 70s Replacement of mines hunters with wooden hull Decrease of the magnetic signature 9/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
COMPOSITE STRUCTURES AT DCNS SURFACE SHIPS La Fayette class frigates (FLF) – 90s Part of superstructures (83 T) Improved steel / GRP joint Radar compatibility of the steel / GRP joint 10/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
COMPOSITE STRUCTURES AT DCNS SURFACE SHIPS Corvettes / OPV Gowind (L’Adroit) - 2010 Single integrated mast Options : composite topside, composite hull for fast versions 11/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
COMPOSITE STRUCTURES AT DCNS SUBMARINES Conning tower Sail plane Decks Sonar dome Antenna cover Rudder 12/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
SUMMARY OF ACCELERATED SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES AGEING TEST PROGRAMMES
SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES AGEING CONDITIONS & AGEING EVALUATION Accelerated ageing conditions : � Temperature : from 40 to 100° C � Duration : 500 – 1000 – 2000 – 4000 – 6000 – 8000 – 24000 hours � Mechanical test samples – plates (500 X 500 mm) – edges protected by resin or silicon mastic � Immersion : demineralized water – artificial salt water – natural salt water � Salt spray � Pressure : 1 – 60 – 400 bars � Hygrothermal cycling (- 20° C / + 70° C) � No loading or static flexural loading � Two / One side(s) exposure Ageing evaluation : � Mechanical tests : tensile – interlaminar shear – compression – 3 point bending � Physico-chemical tests : DSC – IRFT – water sorption – fire reaction tests – DMA � SEM 14/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES WATER SORPTION ( ) exp = − + P a bt c ( ) = exp − + P a bt c 15/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES MAIN RESULTS Immersion at POLYESTER EPOXY VINYLESTER 60 – 70° C Chemical evolution None Not evaluated None Glass transition temperature 5° C 4 à 8° C Maximal water sorption 0,5 to 3 % 2 to 3,5 % 0,3 to 0,5 % Immersion at MODULUS STRENGTH 60 – 70° C 3 point bending No change of 30 to 50 % Interlaminar shear No change of 30 to 40 % Tensile No change of 40 % 16/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES MICROSCOPY 17/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES CAVITATION EROSION – GLASS / EPOXY COMPOSITES 60 50 Volume loss (mm3) 40 30 20 10 0 After step 6 (120 min After step 9 (120 min 0 50 100 150 200 250 300 at 20 to 89 m/s) Time (min) at 20 to 89 m/s + 120 min at 89 m/s ) 18/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
SUMMARY OF ACCELERATED AGEING TEST PROGRAMMES CAVITATION EROSION – GLASS / EPOXY COMPOSITES Hand lay-up Infusion Prepreg 19/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE IN SERVICE EXPERIENCE
IN SERVICE EXPERIENCE SURFACE SHIPS STRUCTURES Impact in monolithic structure Debonding in sandwich panel 21/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE SURFACE SHIPS STRUCTURES Cracks due to corrosion of metallic inserts Decohesion 22/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE SURFACE SHIPS STRUCTURES D area : loss of anti-fouling paint ; gelcoat ; surface filler ; 1-2 plies of woven roving 300 g/m² E area : 1-2 plies of woven roving 300 g/m² 23/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE SUBMARINES STRUCTURES 24/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE MAINTENANCE Every 8 years : sanding, painting Special maintenance : repairing 25/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE MECHANICAL PROPERTIES EVOLUTION BAMO test structure (glass/polyester) – no paint / gel-coat – no mechanical stress (except one explosion test) – 10 years in Lorient : no evolution of the mechanical properties (above and below waterline ) CMT Andromède (glass/polyester) – gel-coat + antifouling paint – in service – 18 years : slight evolution of the mechanical properties � Interlaminar shear strength : - 5 à – 15 % in air ; - 6 à – 19 % in water � Flexural strength : - 12 % in air ; - 28 % in water � Compression modulus : - 14 % in air and in water � Ultimate compression strength : - 14 % in air and in water SM Le Terrible external deck (glass/polyester) – antifouling paint – in service - 35 years : � Interlaminar shear strength : - 4 % � Flexural strength : - 36 % 26/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
IN SERVICE EXPERIENCE SM LE TERRIBLE EXTERNAL DECK 27/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
NATURAL AGEING / NATURAL AGEING / ACCELERATED AGEING ACCELERATED AGEING CORRELATION CORRELATION
NATURAL AGEING / ACCELERATED AGEING CORRELATION FLEXURAL STRENGTH FLEXURAL STRENGTH AGEING CORRESPONDING DURATIONS 160 140 Natural ageing (years) 120 100 80 -41% 60 40 -36% -28% 20 0 0 2000 4000 6000 8000 Accelerated ageing (hours) 29/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
NATURAL AGEING / ACCELERATED AGEING CORRELATION INTERLAMINAR SHEAR STRENGTH ILSS AGEING CORRESPONDING DURATIONS 160 140 -17% Natural ageing (years) 120 100 80 60 40 -14% 20 -7% 0 0 500 1000 1500 2000 Accelerated ageing (hours) 30/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
CONCLUSION CONCLUSION
CONCLUSION Main ageing problems : � Corrosion of metallic inserts � Holes in sandwich structures � Impacts � Assembly / removal � Cavitation erosion Main difficulties in evaluating the ageing of composites in service : � Lack of information concerning initial properties � Imprecise history of the structure � Very few opportunities to study real old structures � Paint and gelcoat protection effects � Materials evolution � Difficulties in specimens preparation 32/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
CONCLUSION Excellent behaviour of composite structures in naval applications. 33/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
THANK YOU FOR YOUR ATTENTION THANK YOU FOR YOUR ATTENTION 34/34 DCNS RESEARCH – Frédérique LE LAY – 24/08/2012
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