Essais & Simulations n°140

DOSSIERSPÉCIAL JEC

DOSSIERSPÉCIAL JEC WORLDINTERVIEWLaunch of a platformto study the mechanical firebehaviour of aeronauticalcompositesINSA Rouen presented the results of the work of two partnerlaboratories: the Materials Physics Group and the InterprofessionalResearch Complex in Aerothermochemistry have been workingon the problem of the fire behaviour of materials which, in viewof the recent air disasters, are at the heart of the concerns ofaeronautical manufacturers.Benoit VieilleDoctor of the University of Franche-Comté and Engineerof the National Superior School of Mechanics andMicrotechnics of Besançon, then Senior Lecturer atthe INSA of Rouen. Appointed Professor in 2019 at theMechanics Department of INSA Rouen, his researchactivities within the Group Laboratory of MaterialsPhysics focus on the thermo-mechanical behaviourin critical conditions of aeronautical composite materials. Adopting a multi-scaleapproach to the constituent elements of the composite structure, his work aimsin particular to characterize/understand/simulate the high-temperature fatiguebehaviour, impact behaviour and damage tolerance, as well as the fire resistance(thermo-mechanical-physicochemical coupling) of reinforced composites.Alexis CoppalleProfessor at INSA Rouen in the Department of Energy andPropulsion. His areas of expertise and research topicsare the thermal degradation of composite materials,fire smoke analysis, analysis and modelling of confinedfires and polluting emissions during the combustion ofbiomassBEFORE YOU PRESENT YOUR LABAND THE PROJECT, WHAT DOYOU FIND OUT ABOUT AVIATIONSAFETY? WHAT FLAWS STILL EXISTON AIRCRAFT, ESPECIALLY IN THEAREA OF FIRE HAZARDS?The recent air disasters have revealedthat the issue of fire is at the heart ofaircraft manufacturers' concerns. Theuse of innovative composite materialsin aeronautical applications is todayconfronted with ever more demandingsafety standards to which it is imperativeto provide reliable and representativeanswers. Understanding the effectsof heat and fire on the physico-chemicalproperties and structural integrityof composites is essential to ensurepassenger safety. However, certificationtests on real structures do not take intoaccount the strong thermo-mechanicalcoupling within composite materials.Manufacturers have thus identified atechnological barrier in the fire resistanceof materials and the demand forappropriate and relevant experimentalcharacterization means is thereforehigh.46 IESSAIS & SIMULATIONS • N°140 • février - mars 2020

BEFORE YOU PRESENT YOUR LABAND THE PROJECT, WHAT DOYOU FIND OUT ABOUT AVIATIONSAFETY? WHAT FLAWS STILLEXIST ON AIRCRAFT, ESPECIALLYIN THE AREA OF FIRE HAZARDS?The recent air disasters have revealedthat the issue of fire is at the heart ofaircraft manufacturers' concerns. Theuse of innovative composite materialsin aeronautical applications istoday confronted with ever moredemanding safety standards to whichit is imperative to provide reliableand representative answers. Understandingthe effects of heat and fireon the physico-chemical propertiesand structural integrity of compositesis essential to ensure passengersafety. However, certification testson real structures do not take intoaccount the strong thermo-mechanicalcoupling within compositematerials. Manufacturers have thusidentified a technological barrier inthe fire resistance of materials andthe demand for appropriate and relevantexperimental characterizationmeans is therefore high.Detailed representation of a test benchWHICH LABORATORIES DOYOU BELONG TO AND CAN YOUPRESENT US THEIR ACTIVITIES/ KNOW-HOW / FIELDS OFAPPLICATION?The Materials Physics Group (GPM) is aJoint Research Unit (UMR 6634) structuredinto five scientific departmentsthat bring together about 170 people.It is specialized in scientific instrumentationand the study of materials fromthe finest scales to the macroscopicscale in order to explain their physicaland mechanical properties. Part of theGPM's activities is concerned with thestudy of thermo-mechanical couplingsin composite materials for aeronauticalapplications. In this industrial logic,various problems are investigated:fatigue behaviour at high temperature,fire resistance, impact and damage tolerance.In addition, another GPM teamalso has strong expertise in the field ofthermal analysis of polymers.Coria is a Joint Research Unit (UMR)attached to the Institute of Engineeringand Systems (INSIS) of the CNRS, theUniversity of Rouen and the Instituteof Applied Sciences (INSA) of Rouen.Coria's fields of research cover fundamentaland applied studies on reactiveor non-reactive flows: two-phaseflows, turbulent mixing phenomena,combustion, plasmas, etc. The physicalmechanisms and processes leadingto the reduction of pollutant emissionsin reactive systems are priority researchareas. This research has applications inthe fields of energy and transport. Inparticular, the laboratory carries outstudies on the combustion of solidswith the application of biomass valorisation,as well as studies on the behaviourunder flame of composite materialsused for transport.WHEN DID YOU STARTRESEARCHING THE FIREBEHAVIOUR OF MATERIALS?Halfway between thermal and mechanicalexpertise, this collaboration betweenthe GPM and Coria laboratories wasinitiated in 2013. The question that aroseat the time was simple:Thermal decomposition