REVIEWARTICLEDigitalImageCorrelation:fromDisplacementMeasurementtoIdentificationofElasticProperties–aReviewF.Hild*andS.Roux†*LMT-Cachan,ENS-Cachan/CNRSUMR8535/Universite´Paris6,61avenueduPre´sidentWilson,F-94235CachanCedex,France†LaboratoireSurfaceduVerreetInterfaces,UMR125CNRS/SaintGobain,39quaiLucienLefranc,F-93303AubervilliersCedex,FranceABSTRACT:Thecurrentstateoftheartofdigitalimagecorrelation,wheredisplacementscanbedeterminedforvalueslessthanonepixel,enablesonetobettercharacterisethebehaviourofmaterialsandtheresponseofstructurestoexternalloads.Ageneralpresentationoftheextractionofdisplacementfieldsfrompicturestakenatdifferentinstantsduringanexperimentisgiven.Dif-ferentstrategiescanbefollowedtodeterminesubpixeldisplacements.Newidentificationproce-duresarethendevisedmakinguseoffull-fieldmeasurements.Apriorioraposterioriroutescanbefollowed.TheyareillustratedontheanalysisofaBraziliandisktest.KEYWORDS:Braziliandisktest,correlationalgorithm,integratedapproach,kinematicmeasurements,photomechanics1.Introduction•toperformheterogeneoustestsonmaterials[10]orstructures[11]forwhichsinglemeasurementsWiththedevelopmentofcomplexthermomechani-(e.g.bystraingauges,extensometers,clipgauges)calexperiments,full-fielddisplacementandstrainarenotsufficienttofullymonitoranexperiment,measurementsareoftenneeded.Inrecentyears,theandparticularlywhenthespatialheterogeneitydevelopmentofrobust,fastandaffordabletoolsforisnotknownapriori(e.g.strainlocalisationfull-fieldkinematicmeasurementspromptsmoreand[12,13],damagelocalisation[14]orcrackiniti-moreexperimentaliststoresorttosuchtechniques.ationandpropagation[15,16]);Thelattercanbeadaptedtoevaluate2Dor3Ddis-•tostudyanexperimentbyusingcontactlesstech-placementfieldsofthesurfaceofsolids[1]andmoreniques.Thisprovidesusefulsolutionstoaggres-recentlyeveninthebulkofasolid[2].Moregener-sive,hot,corrosiveenvironments,orverysoftally,full-fieldmeasurementsconstituteanoppor-solidsforwhichgaugesarenotadapted(e.g.poly-tunitytobridgethe