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摘要: 利用分离式霍布金森压杆实验系统(SHPB)对2种典型的软岩砂质、泥岩进行动态力学性能测试, 测试的应力应变曲线表现出显著的应变硬化和塑性流动等复杂的动态力学特性。基于实验结果,在朱-王-唐 模型的基础上,并且考虑软岩本身结构缺陷的影响,建立了一种适应软岩材料的黏弹性统计损伤模型。该模 型由2个Maxwell体和1个损伤体并联组成,2个Maxwell体用来描述对软岩高分子材料的高低应变率响应 以及软岩材料在动载作用下的塑性变形特性,考虑软岩材料本身缺陷的影响,用一个损伤体代替朱-王-唐模 型中的非弹性弹簧。利用黏弹性统计损伤模型对不同应变率下软岩材料的动态应力应变曲线进行拟合,拟合 曲线与测试曲线一致性良好。Abstract: Twokindsoftypicalsoftrockmaterials,mudstoneandsandymudstone,werechosenasthe researchedobjectives.Andtheiruniaxialdynamiccompressivepropertiesweretestedbyusingasplit Hopkinsonpressurebarsystem.Theobtainedstress-straincurvestakeoncomplexdynamiccharacteristicssuchasdistinctstrainhardeningandplasticfloweffects. Withaviewtotheaboveexperimentalresults, aviscoelasticstatisticaldamagemodelwasproposedbasedontheZhu-Wang-Tangmodel byconsideringtheinfluencesofdefectsinsoftrockmaterials.Theproposedmodelwasmadeupof twoMaxwellelementsandonestatisticaldamageelementinparallelconnection,inwhichthetwo Maxwellelementswithdifferentrelaxingtimesreflectingtheviscoelasticresponsesofsoftrockmaterialsatlowandhighstrainrates, respectively,andthestatisticaldamageelementtakingtheplaceof thenonlinearspringintheZhu-Wang-Tangmodel.Theexperimentaldatawerefittedtotheproposed model.Thefittedstress-traincurvesatdifferentstrainratesareinagreementwiththeexperimental ones
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Key words:
- solidmechanics /
- viscoelasticstatisticaldamagemodel /
- SHPB /
- softrock /
- dynamicmechanicalproperties /
- curvefitting
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