ECC-Design-Approach-中文.ppt

ECCDesignApproach SoutheastUniversity Nanjing ChinaMay 2006VictorLiE BenjaminWylieCollegiateChairProfessorofCivilandEnvironmentalEngineeringProfessorofMaterialsScienceandEngineeringUniversityofMichigan AnnArbor MI48105USA 2 PresentationOutline报告提纲 ECCMicromechanics细观力学Fiber MatrixInterfaceTailoring纤维 基体界面设计MatrixTailoring基体设计TheoryVerifications理论验证 3 EngineeredCementitiousComposites工程水泥基复合材料 WhatisECC 什么是ECCAclassofHPFRCC一种高性能纤维增强水泥基复合材料Strain hardening应变硬化Lowfibercontent低纤维含量Micromechanicsbaseddesign基于细观力学设计 CompositeECC SteelDeckMiharaBridgeinHokkaido Japan 2004 4 OverallDesignScheme设计框架 ductility otherperformances延性 其他性能 Achievinghighperformancethroughcomponenttailoring通过对组份的优化设计获得高性能 Fiber纤维 Interface界面 Matrix基体 5 CompositeDesignApproach复合设计方法 FlatCrackPropagation平直裂缝的扩展 TensionSofteningFRC应变软化的FRC Strain hardeningECC应变硬化的ECC 6 MicromechanicsBasedDesignforFlatCrackPropagation基于细观力学设计的平直裂缝扩展 Micromechanics细观力学 Steady StateCrackAnalysesSpringCapacityAnalyses稳态裂缝分析 弹簧能力分析 Fiber Matrix Interface纤维 基体 界面 7 BridgingFibersasNon linearSprings非线性弹簧 桥接纤维 d 0 100mm 8 SteadyStateCrackingAnalyses稳态开裂分析 EnergychangesfromState1to2 Energybalance B 能量变化 能量平衡 9 EnergyBalanceInterpretation能量平衡解析 B Duringsteadystatecrackpropagation 稳定裂缝扩展阶段 10 ConditionforStrain Hardening应变硬化条件 RHS crack tiptoughness裂尖韧性 f matrixcomposition LHS C f fiber interface ECCCompositeDesignBasis复合设计基础 基体组成 纤维 界面 桥接纤维的弹簧定律 11 MicromechanicalModelforsB dCurve细观力学模型 sB dSpringLaw 基体开裂平面 12 ModelPredict 模型预测的曲线 13 MicromechanicsDesignStrategy forfiberandinterface Control spring behaviortoachieve控制弹簧行为获得MaxC f Vf fiberproperties interfaceproperties CriticalfibervolumetoconvertFRC ECC控制临界纤维体积率使FRC转变为ECC 应变硬化 拉伸软化 脆性 14 InterfaceDesign界面设计 临界纤维体积率 目标 15 Tailoring SurfaceCoatingControlofInterfaceProperties表面涂覆控制界面性能 CoatingbyKurarayCo Ltd 表面涂覆量 摩擦粘结强度 未处理纤维 目标 16 Result StrainCapacityIncreaseswithSurfaceCoatingControl表面涂覆后应变能力增加 17 SurfaceCoatingEffectonFiberDamage表面涂覆对纤维损伤的影响 NoCoating未涂覆 18 criticalflawsizecmc临界缺陷尺寸 s s Compositestress strain CompositeDesignApproach复合设计方法 MicrocrackInitiation微裂纹引发 fiber Flaw缺陷 Matrix基体 Fiberbridgingbehavioratdifferentplanes s sci scu 纤维 19 MatrixTailoring基体设计 Ductility延性 Strength强度 Sustainability可持续性 Lightweight轻质 matrix interface composite 20 VariationofTensileBehavior拉伸行为的变化 PVA ECC Vf 2 Extremevariabilitycase 21 CrackingStrengthandFlawSize开裂强度和缺陷尺寸 s s0 sss ss 0 c c flawsize 0 smallerflawsize缺陷尺寸变小 22 TailoringofFlawSizeDistributionforSaturatedMultipleCracking饱和多缝开裂的缺陷分布设计 SuperimposeartificialflawswithprescribedsizesArtificialflaws plastic bubbles lightweightaggregates etc cmc func fiberbridging matrixtoughness 23 LEFMFailedtoPredictCrackingStrengthLEFM预测开裂强度失败 10mm ScaleoftheflawstoosmalltoapplyLEFM缺陷太小 LEFM不适用 24 CohesiveCrackModel粘着裂缝模型 w w w 2a GF 100 m 25 FEMModelofCracking开裂模型 interfaceelements mortarelements 80 x105mm2 Dplateuniaxialtensileload 26 CrackingStrengthofMortar砂浆开裂强度 27 CrackingStrengthofPVA ECC开裂强度 28 InherentFlawsinPVA ECC固有缺陷 s c 0 8 fa c 0 8 w b 0 24 PVAVf 2 0 10mm 29 ModelingofOptimalArtificialFlawSize人工缺陷优化模型 30 EffectofIntroducingArtificialFlaws引进人工缺陷的效果 F l a w S i z e m m Lightweightaggregatessize 3 5mm s c 0 8 fa c 0 8 w b 0 24 PVAVf 2 0 轻集料 31 EffectofIntroducingArtificialFlaws引入人工缺陷的效果 s c 0 8 fa c 1 2 w b 0 24 PVAVf 2 0 age 28days watercured 32 DesignTheoryVerification设计理论验证 PE ECC MatrixToughnessEffect Lietal 1995 33 DesignTheoryVerification设计理论验证 PP ECC Takashimaetal 2001 34 DesignTheoryVerification设计理论验证 CorrelationbetweenJb JtipandCompositeDuctility Jb Jtip Jb Jtip和复合延性的关系 35 ECCEngineeredCementitiousComposite Micromechanicsassistsinfiber interface andmatrixtailoring基于细观力学的纤维 界面和基体优化OptimizationleadstohighductilitywithminimumVf优化的结果是低纤维掺量 高延性ECC Advancedmaterial designconcept先进材料 设计理念 36 DesignAnalogy PerformanceDifferenceResultingfromMechanicsBasedDesign Non engineered Engineered 基于力学设计的性能差异 37 References Li V C D K MishraandH C Wu MatrixDesignforPseudoStrain HardeningFiberReinforcedCementitiousComposites RILEMJ MaterialsandStructures Vol 28 No 183 pp 586 595 1995 Li V C EngineeredCementitiousComposites TailoredCompositesThroughMicromechanicalModeling inFiberReinforcedConcrete PresentandtheFutureeditedbyN Banthia A Bentur andA Mufti CanadianSocietyforCivilEngineering Montreal pp 64 97 1998 Li V C FromMicromechanicstoStructuralEngineering theDesignofCementitiousCompositesforCivilEngineeringApplications JSCEJ ofStruc MechanicsandEarthquakeEngineering Vol 10 No 2 pp 37 48 1993 Li V C andLeung C K Y SteadyStateandMultipleCrackingofShortRandomFiberComposites ASCEJ ofEngineeringMechanics Vol 118 No 11 pp 2246 2264 1992 Lin Z T KandaandV C Li OnInterfacePropertyCharacterizationandPerformanceofFiberReinforcedCementitiousComposites J ConcreteScienceandEngineering RILEM Vol 1 pp 173 184 1999 Li V C C Wu S Wang