Forsomelargelydamagedships,theconventionalmethodsareunadaptabletoestimatetheirdynamiccharacteristicsastoshipswithsymmetricalhullsection.Basedondryhullmodalanalysisofflexure-torsioncouplingvibrationofunsymmetricalshipstructuresaboutlongitudinalcenterline,atransfermatrixmethodtocalculatethedynamiccharacteristicsispresented.Takenbothsheareffectandwarpingdeformationsintoaccount,thepointandfieldtransfermatricesarederived,andtheinflu-