简介:TheSelf-SimilarCrackExpansion(SSCE)methodisproposedtoevaluatestressintensi-tyfactorsatcracktips,wherebystressintensityfactorsofacrackcanbedeterminedbythecrackopeningdisplacementoverthecrack,notjustbythelocaldisplacementaroundthecracktip.Thecrackexpansionrateisestimatedbytakingadvantageofthecrackself-similarity.Therefore,theaccuracyofthecalculationisimproved.Thesingularintegralsoncracktipelementsarealsoanalyzedandarepre-ciselyevaluatedintermsofaspecialintegralanalysis.Combinationofthesetwotechniquesgreatlyin-creasestheaccuracyinestimatingthestressdistributionaroundthecracktip.Avarietyoftwo-dimen-sionalcracks,suchassubsurfacecracks,edgecracks,andtheirinteractionsarecalculatedintermsoftheself-similarexpansionrate.Solutionsaresatisfiedwitherrorslessthan0.5%ascomparedwiththeanalyticalsolutions.Basedonthecalculationsofthecrackinteractions,atheoryforcrackinteractionsisproposedsuchthatforagroupofalignedcracksthesummationofthesquareofSIFsattherighttipsofcracksisalwaysequaltothatatthelefttipsofcracks.ThistheorywasprovedbythemehtodofSelf-SimilarCrackExpansioninthispaper.
简介:Formulationintermsofhypersingularintegralequationsfortheinteractionbetweenstraightandcurvedcracksinplaneelasticityisobtainedusingthecomplexvariablefunctionsmethod.Thecurvedlengthcoordinatemethodandasuitablenumericalschemeareusedtosolvesuchintegralsnumericallyfortheunknownfunction,whicharelaterusedtofindthestressintensityfactor,SIF.
简介:Thedynamicstressintensityfactorhistoryforahalfplanecrackinanotherwiseunboundedelasticbody,withthecrackfacessubjectedtoatractiondistributionconsistingoftwopairsofcombinedmodepointloadsthatmoveinadirectionperpendiculartothecrackedgeisconsidered.Theanalyticexpressionforthecombinedmodestressintensityfactorsasafunctionoftimeforanypointalongthecrackedgeisobtained.ThemethodofsolutionisbasedontheapplicationofintegraltransformtogetherwiththeWiener-HopftechniqueandtheCagniard-deHoopmethod.Somefeaturesofthesolutionarediscussedandgraphicalresultsforvariouspointloadspeedsarepresented.