激光沖擊Fe-Ni合金殘余應力場的數(shù)值模擬.pdf

1、江蘇大學碩士學位論文激光沖擊FeNi合金殘余應力場的數(shù)值模擬姓名：武敬偉申請學位級別：碩士專業(yè)：機械制造及其自動化指導教師：花銀群20071213江蘇大學碩士學位論文ABSTRACTBasedonthemechanismofLSPinducingresidualstressfield，inthispaper，theresidualstressfieldofFe—Nialloywassimulatedandthenexperimental

2、researchwasmadeonLSPofFe—NialloyThemaincontentswereasfollowing：ThemechanismoflasershockwavewasdescribedFabbromodelanditscorrectedmodelintheconfinedmodewereanalyzedAccordingtothetheoryofplasticelasticitydynamicsandthetheo

3、ryofshockwave，theconstitutiveequationsofmaterialwereanalyzedwhenlasershockwavepropagatedinmaterialinonedimensionstraincompressCombinedwiththeconstitutiveequationsinonedimensionstraincompress，theformingprocessingofresidua

4、lstressfieldinducedbyLSPWasanalyzedThenthemaininfluencingfactorsofresidualstressfieldwereanalyzed，especiallytheshockparameterBasedonANSYS／LS—DYNAsoftware，theFEAanalysismodelWasfounded，consideringthefiniteelementtheorySom

5、ekeyproblemswerediscussedTheresultsofnumericalsimulationwereanalyzedTheeffectsoflasershockparametersontheresidualstressfieldofFeNialloywerestudiedbynumericalsimulation，whichindicatedthat：Thepeaksurfaceresidualcompressive

6、stressincreasedasthelaserpowerdensityincreasedwhenthelaserpowerdensityWasbelowafixedvalue，andthendecreasedAtthesametime，thedepthoftheresidualcompressivestressWasincreasingallthetimeThemaximumandthedepthoftheresidualcompr

7、essivestressincreasedasthelaserpulsedurationincreased，whichshoweditcouldimprovetheresidualcompressivestressfieldbyincreasingthelaserpulsedurationThesimulatedresultsalso。revealedthatincreasingthelaserspotsizecouldresulted

8、inanincreaseinthemaximumandthedepthoftheresidualcompressivestress，especiallythelatterExperimentalresearchWasmadeonLSPofFeNialloytheresultsoftheexperimentwereanalyzedTheresultsindicatedthattheaveragemicrohardnessoftheshoc

9、kzoneofthesamplesincreasedbyabout16％TheresultsalsoshowedLSPinducedmartensitictransformation、cellulardislocationofhi曲densi哆andtwinIncontrast、加mFEAandexperimentaldata，thesimulateddataofresidualstressfieldWaswellconsistentw