简介：AlthoughMorisonequationisoftenappliedforsimulatinghydrodynamicforceofmarinestructure,itmaygivepoorresultswhennon-linearbehaviorissevereorrandomwaveisencountered.ThisleadstosomemodificationsofMorisonequationorothermethodsforpredictinghydrodynamicforce.Oneofthemisthesystemidentificationtechnique.Inthispaper,NARMAXmodeltheoryisfirstlyusedtoidentifythehydrodynamicsystemofheavedampingplates,whicharecommonlyinstalledonsparplatform.Bothlinearandnon-linearmodelsareobtained.ThecomparisonsbetweenthepredictedresultsandmeasureddataindicatethatNARMAXmodelcanpredicthydrodynamicforceofaheavedampingplateverywell.Themeasureddataforidentificationoriginatefromforcedoscillationtests,whicharerandomrecordswithgivenspectrum.Theforcedoscillationformsinexperimentalsocontainsimpleharmonic,multi-frequencyones.