In orderto solvestructural multi-damageidentification problem,atwo-stage
identificationmethodbasedontheparticleswarm optimization (PSO)algorithm andthe
Bayesiantheorywasproposed.Inthismethod,structuralmodalstrainenergy (MSE)and
frequencyareconsideredastwoinformationsources,andthe methodsbasedonfrequency
changeand MSE dissipationratioareutilizedtoextractdamageinformation.Then,the
Bayesiantheoryisutilizedtointegratethetwoinformationsourcesandpreliminarilydetect
structuraldamagelocations.Finally,the PSO algorithm isadoptedto preciselyidentify
structuraldamagelocationsandextents.Inordertoimprovetheidentificationresultsofa
simplePSOalgorithm,threeimprovedstrategies,particleposition mutation,elitistmicro-
searchanddoubleconvergencecriterion,werepresented.Thesimulationresultsforatwo-
dimensionaltrussstructureshowthattheBayesiantheorycanidentifythesuspecteddamage
locations,theimproved PSO algorithm can preciselydetectthedamageextent,andthe
identificationprecisionofthePSOalgorithm withthethreeimprovedstrategiesisobviously
betterthanthoseoftheotherPSOalgorithmsandthegeneticalgorithm.