激光冲击feni合金残余应力场的数值模拟

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1、江苏大学硕士学位论文ABSTRACTBasedonthemechanismofLSPinducingresidualstressfield，inthispaper，theresidualstressfieldofFe—NialloywassimulatedandthenexperimentalresearchwasmadeonLSPofFe—Nialloy．Themaincontentswereasfollowing：Themechanismoflasershockwavewasdescribed．Fabbromodelanditscorrect

2、edmodelintheconfinedmodewereanalyzed．Accordingtothetheoryofplastic-elasticitydynamicsandthetheoryofshockwave，theconstitutiveequationsofmaterialwereanalyzedwhenlasershockwavepropagatedinmaterialinonedimensionstraincompress．Combinedwiththeconstitutiveequationsinonedimensionstra

3、incompress，theformingprocessingofresidualstressfieldinducedbyLSPWasanalyzed．Thenthemaininfluencingfactorsofresidualstressfieldwereanalyzed，especiallytheshockparameter．BasedonANSYS／LS—DYNAsoftware，theFEAanalysismodelWasfounded，consideringthefiniteelementtheory．Somekeyproblemsw

4、erediscussed．Theresultsofnumericalsimulationwereanalyzed．TheeffectsoflasershockparametersontheresidualstressfieldofFe-Nialloywerestudiedbynumericalsimulation，whichindicatedthat：Thepeaksurfaceresidualcompressivestressincreasedasthelaserpowerdensityincreasedwhenthelaserpowerden

5、sityWasbelowafixedvalue，andthendecreased．Atthesametime，thedepthoftheresidualcompressivestressWasincreasingallthetime．Themaximumandthedepthoftheresidualcompressivestressincreasedasthelaserpulsedurationincreased，whichshoweditcouldimprovetheresidualcompressivestressfieldbyincrea

6、singthelaserpulseduration．Thesimulatedresultsalso。revealedthatincreasingthelaserspotsizecouldresultedinanincreaseinthemaximumandthedepthoftheresidualcompressivestress，especiallythelatter．ExperimentalresearchWasmadeonLSPofFe-Nialloy,theresultsoftheexperimentwereanalyzed．Theres

7、ultsindicatedthattheaveragemicrohardnessoftheshockzoneofthesamplesincreasedbyabout16％．TheresultsalsoshowedLSPinducedmartensitictransformation、cellulardislocationofhi曲densi哆andtwin．Incontrast、加mFEAandexperimentaldata，thesimulateddataofresidualstressfieldWaswellconsistentwithth

8、eexperimentaldata．KEYWORDS：lasershockprocessing，Fe-Nialloy,residuals