摘要
Amethodisdevelopedforcyclicelastoplasticanalysisacrossmicro/meso/macroscaleswhichiseffectiveforthequantitativetransitionofphysicalvariablesandforevaluatingthesizeeffectsofmicrostruc-tures.Byusingtheimprovedself-consistentsehemeproposedbyFanandcarryingoutadelicatemesoscop-icanalysisbasedonashear-lagmodel,thesizeeffectsincludingthethicknessofhardandsoftlayersrelativetotheinclusiondimensionareobtainedontheoverallelastoplasticresponsesofmaterialsupto50cycles.Thedominantcharacteristicsoftheanalysisrarethatthecharacteristicdimensionsofamicrostructuresuchasthethicknessofthelayersandtheinclusiondimensioncanbeexplicitlyincorporatedintotheformulation.Resultsofnumericalanalysisusingonly4plasticconstantsshowthatthethickerthelayerrelativetothein-clusionsize,thesofterthematerialinproducingmoreplasticstrainvaluesforagivenappliedstressampli-tude.Thisisinagreementwiththewell-knownexperimentalrulethattheyieldstrengthoflayeredstructuresisinverselyproportionultothesquarerootofthespacingbetweenlayers.Itisfoundthatratchetingdependsverymuchonthesizeofthelayered-structureandthatthethinnertherelativethicknessofthelayerthelesstheratchetiugdisplacement.Thisfindingmaybeusedtoexplainwhyphenomenologicalmodelsonratchetingarenotquitesuccessfulsofar,indicatingthesignificanceofaerossscaleanalysisinunderstandingissueswhichhaveexistedforalongtime.
出版日期
2002年01月11日(中国期刊网平台首次上网日期,不代表论文的发表时间)