摘要
能量的耗散和晶体显微结构的运动与演变有关。根据金属显微结构稳定性原理 ,利用自由能的变化将微观角度的显微结构变化与宏观的疲劳损伤过程联系起来 ,并用储能定义损伤变量。提出获得储能的数值方法 ,建立基于不可逆能量耗散的疲劳损伤演化模型 ;并对该模型用 40CrNiMoA的两级加载试验进行验证 。
Thefatiguedamageprocessdissipatesenergy .Theenergydissipationisrelevanttothemotionandevolutionofcrystal microstructures .Thestabilityofthemicrostructuredecreasesuntilreachesthecriticalstateoffailure .Inthisstage ,thefreeenergyin creasesmonotonically .Thus ,thefatiguedamageprocesscanbeconnectedtothevariationofmicrostructuresduringfatigue ,utilizingthe changeoffreeenergy .Adamagevariablewasdefinedbythestoredenergy ,whichisapproximatelyequaltothefreeenergy .Thisdam agevariablehasclearphysicalmeaning .Theequationofenergydissipationwasderivedbythefirstthermodynamiclaw .Thestoredener gywascomputedbythetemperatureresponsemeasuredduringfatiguetest ,utilizingthefiniteelementmethod .Onthisfoundation ,afa tiguedamagemodelbasedontheirreversibleenergydissipationwasestablished .Thepredictedresultfitswellwiththetwo levelfatigue testresultof 40CrNiMoA .
出处
《机械强度》
CAS
CSCD
北大核心
2004年第5期522-525,共4页
Journal of Mechanical Strength
关键词
疲劳
损伤
能量耗散
Fatigue
Damage
Energydissipation
