简介:Inthelightofagrowingneedforfracturecontrolofrapidcrackpropagation(RCP)ingaspipelines,aprogramPFRAC(PipelineFRactureAnalysisCode)hasbeendevelopedtoanalysethcvariousevents.Inthispaper,byusingPFRACforthesimulationofaxialcrackpropagationingaspipelines,anumberofdynamicanalysisissuesrclatingtoboundaryeffectsforuncrackedandcrackedpipesareinvestigated.Thisindicatesthattheboundaryconditionsalongthelengthofthepipeplayanimportantroleforfractureanalysisinthepipe.Incontrast.theboundarycondutionsatthcendsofalongpipelinehavelittleeffectonthedynamicfractureevents.
简介:Inthispaper,ageneralsolutionforthree-dimensionalstaticpiezothermoelasticprob-lemsofcrystalclass6mmsolidsispresented.Tnegeneralsolutioninvolvesfourpiezoelasticpotentialfunctionsandapiezothermoelasticpotentialfunction,ofwhichfourpiezoelasticpotentialfunctionsaregovernedbyweightedharmonicdifferentia[equations.ComparedwiththegeneralsolutiongivenbyAshidaetal.,inwhichsevenpotentialfunctionsareintroduced,thegeneralsolutionproposedinthepresentpaperismorerigorouslyderived.Moreover,ithasasimpleformandisconvenientforappli-cation.Asanillustrativeexample,theproblemofapyroelectrichalf-spacesubjectedtoaxisymmetricheatingisstudied.Numericalresultsofdisplacements,stresses,electricpotentialandelectricdisplace-mentsareobtainedforacadmiumselenidehalf-space.Thermallyinduceddisplacementsandstressdis-tributionarecomparedwiththoseobtainedforthesamematerialwithoutpiezoelectricandpyroelectriceffects.
简介:Westudyelectromechanicalfieldsintheanti-planedeformationofaninfinitemediumofpiezoelectricmaterialsof6mmsymmetrywithacircularcylindricalhole.Thetheoryofelectroelasticdielectricswithelectricfieldgradientintheconstitutiverelationsisused.Specialattentionispaidtothefieldsnearthesurfaceofthehole.