简介：Thedynamicresponseofastrain-softeningbeamsubjectedtoatransverseimpulsiveonitstipisinvestigated.Asofteningmoment-curvaturerelationisassumedforthebeamandaclosedformsolutionisobtainedforaspecialkindofload,whichshowsthatthereexistsasofteningregioninthebeamandthisre-gionpropagatesalongthebeam.Thisresultindicatesthat,exceptforthepossiblediscretesofteningpointswithrotationdiscontinuitycausedbythedeformationlocalization,theexistenceofthesofteningregionanditstravellingalongthebeamaretheessentialfeaturesofthedynamicresponseofastrain-softeningbeam.Theresultsalsoshowthatthefailureofthebeamshouldtakeplaceunderaspecialloadandthecriticalconditiononwhichthedynamicfailureoccursisgiven.

简介：Anapproximatemethodfordescribingtheplastichardening-softeningbehaviourofcircularpipessubjectedtopurebendingispresented.Theo-reticalestimationbasedontheuniformovalizationmodelandlocalcollapsemodelproposedinthepaperisincorporatedtogiveseveralsimpleformulationswithrea-sonableaccuracyfordeterminingtherelationshipbetweenbendingmoment(M)andcurvature(k)inthepurelybendedpipes.Attentionisfocusedonthecriticalcur-vatureassociatedwithmaximumresistantmomentandthemaximumchangeintheoriginaldiameterbeforetheendofuniformovalizationstageaswellasthelocalcollapsebehaviour.Somecomparisonsbetweenanalyticalresultsandexperimentalresultsaremadeinordertoexaminethetheory.

简介：Onthebasisofplasticityandfracturemechanicsforquasi-brittlematerials,thisarticlepresentedaconstitutivemodelforgradualsofteningbehaviorofjointsofgeomaterials.Correspondingnumericaltestsarecarriedoutatthelocallevel.Characteristicsofthemodelproposedare1)plasticsofteninganddilatancybehavioraredirectlyrelatedtothefractureprocessofjoint,andmuchlessmaterialandmodelparametersarerequiredcomparedwiththoseproposedbyreferences;2)theprocessofdecohesioncoupledwithfrictionalslidingatbothmicro-scaleandmacro-scaleisdescribed.