资源描述：
《环氧沥青混凝土裂纹起裂与失稳扩展的临界特征》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。
1、第32卷第1期Vol.32No.1工程力学2015年1月Jan.2015ENGINEERINGMECHANICS96文章编号：1000-4750(2015)01-0096-08环氧沥青混凝土裂纹起裂与失稳扩展的临界特征12钱振东，王江洋(1.东南大学智能运输系统研究中心，江苏，南京210018；2.苏州市公路管理处，江苏，苏州215007)摘要：为了获取环氧沥青混凝土的裂纹起裂与失稳扩展临界点，重构了环氧沥青混凝土非均质(集料、砂浆和空隙)多层次(矿料级配)结构三维虚拟试件，采用离散元方法实施了单边切口小梁虚拟三点弯曲试验，借助数字摄像法捕捉了
2、室内小梁试件表面裂纹发展情况，分析了裂缝发展过程中裂缝尖端张开位移(CTOD)和裂缝口张开位移(CMOD)之间的变化关系。研究结果表明：裂尖张开位移δ25参数的使用为理解实际流入断裂带用于裂缝扩展的那部分能量开辟了一条新思路；裂缝尖端张开位移和裂缝口张开位移关系曲线的两个转折点描述了裂缝起裂和临界失稳扩展状态，环氧沥青混凝土断裂过程中裂缝的扩展经历了起裂、稳定扩展和失稳扩展3个阶段；δ25-CMOD曲线分析法可以作为研究沥青混凝土材料断裂行为的辅助手段。关键词：环氧沥青混凝土；三维离散元方法；虚拟断裂试验；裂尖张开位移；裂缝口张开位移中图分类号
3、：U414文献标志码：Adoi:10.6052/j.issn.1000-4750.2013.07.0666CRITICALCHARACTERIZATIONOFCRACKINITIATIONANDUNSTABLEPROPAGATIONFOREPOXYASPHALTCONCRETE12QIANZhen-dong,WANGJiang-yang(1.IntelligentTransportSystemResearchCenter,SoutheastUniversity,Nanjing,Jiangsu210018,China;2.SuzhouHighwa
4、yBureau,Suzhou,Jiangsu215007,China)Abstract:Inordertodeterminethecriticalpointsofthecrackinitiationandunstablepropagationforepoxyasphaltconcrete(EAC),firstly,athree-dimensional(3D)virtualspecimenofEACwithheterogeneous(coarseaggregates,asphaltmasticandairvoids)andmultilayer(a
5、ggregategradation)morphologicalfeatureswasreconstructed.Secondly,thevirtualthree-pointbendingtestofasingle-edgenotchedbeamwasimplementedusingthediscreteelementmethod(DEM),andadigitalcameramethodwasusedtocapturethesurfacecrackdevelopmentoftheexperimentalbeamspecimen.Finally,t
6、hechangingrelationshipbetweenthecracktipopeningdisplacement(CTOD)andthecrackmouthopeningdisplacement(CMOD)throughoutthecrackdevelopmentwasanalyzed.Theresultsindicatethattheintroductionofδ25representingCTODprovidesanewideaforunderstandingtheenergyoccurringinthefracturezoneuse
7、dforcrackpropagating.Additionally,thetwogoverningpointsontherelationshipcurvebetweenCTODandCMODapproximatelydescribetheinitiationandcriticalunstablepropagationofcracks,respectively.Meanwhile,thecrackdevelopmentofEACincludesthreestages,namely,initiation,stableandunstablepropa
8、gation.Furthermore,itisfoundthattheanalysismethodbasedontheδ25-CMODcurvecan
