简介:Themainobjectiveofthispaperistostudythesingularnatureofthecrack-tipstressandelectricdisplacementfieldinafunctionallygradientpiezoelectricmediumhavingmaterialcoefficientswithadiscontinuousderivative.Theproblemisconsideredforthesimplestpossibleloadingandgeometry,namely,theanti-planeshearstressandelectricdisplacementin-planeoftwobondedhalfspacesinwhichthecrackisparalleltotheinterface.Itisshownthatthesquare-rootsingularityofthecrack-tipstressfieldandelectricdisplacementfieldisunaffectedbythediscontinuityinthederivativeofthematerialcoefficients.Theprob-lemissolvedforthecaseofafinitecrackandextensiveresultsaregivenforthestressintensityfactors,elec-tricdisplacementintensityfactors,andtheenergyreleaserate.
简介:Theproblemofananti-planeGriffithcrackmovingalongtheinterfaceofdissimilarpiezoelectricmaterialsissolvedbyusingtheintegraltransformtechnique.Itisshownfromtheresultthattheintensityfactorsofanti-planestressandelectricdisplacementaroundthecracktiparedepen-dentonthespeedoftheGriffithcrackaswellasthematerialcoefficients.Whenthetwopiezoelectricmaterialsareidentical,thepresentresultwillbereducedtotheresultfortheproblemofananti-planemovingGriffithcrackinhomogeneouspiezoelectricmaterials.
简介:Inthispaper,thescatteringofharmonicantiplaneshearwavesbytwofinitecracksisstudiedusingthenon-localtheory.TheFouriertransformisappliedandamixedboundaryvalueprob-lemisformulated.Thenasetoftripleintegralequationsissolvedusinganewmethod,namelySchmidt’smethod,ThismethodismoreexactandmorereasonablethanEringen’sforsolvingthiskindofproblem.Theresultofthestressnearthecracktipwasobtained.Contrarytotheclassicalelas-ticitysolution,itisfoundthatnostresssingularityispresentatthecracktip,whichcanexplaintheproblemofmacroscopicandmicroscopicmechanics.
简介:Inthispaper,thebehavioroftwocollinearcracksinmagneto-electro-elasticcompositematerialunderanti-planeshearstressloadingisstudiedbytheSchmidtmethodforpermeableelectricboundaryconditions.ByusingtheFouriertransform,theproblemcanbesolvedwithasetoftripleintegralequationsinwhichtheunknownvariableisthejumpofdisplacementsacrossthecracksurfaces.Insolvingthetripleintegralequations,theunknownvariableisexpandedinaseriesofJacobipolynomials.Numericalsolutionsareobtained.Itisshownthatthestressfieldisindependentoftheelectricfieldandthemagneticflux.
简介:Westudyelectromechanicalfieldsintheanti-planedeformationofaninfinitemediumofpiezoelectricmaterialsof6mmsymmetrywithacircularcylindricalhole.Thetheoryofelectroelasticdielectricswithelectricfieldgradientintheconstitutiverelationsisused.Specialattentionispaidtothefieldsnearthesurfaceofthehole.