摘要:
对含层理的煤岩试样进行巴西圆盘劈裂实验和有限元法-离散元法(FDEM)数值模拟, 结果表明层理角度对劈裂破坏模式和抗拉强度有明显影响。 随着层理角度不断增大,可将劈裂 破坏模式划分为4类:垂直层理面的张拉破坏;折线形张拉-剪切复合型破坏;沿层理面的剪切破 坏;沿层理面的张拉破坏。 对抗拉强度值进行分析可知:当垂直于层理面加载时,层理角度影响 最小,抗拉强度等同于煤试样基质的抗拉强度;随着层理角度增大,抗拉强度逐渐减小;平行于层 理方向加载时,抗拉强度最小。 此外,从能量角度分析可知:随着层理角度增大,试样破坏所耗散 的能量越来越少,破坏越容易。
Abstract:
Inthispaper,Braziliandiscsplittingtestsoncoalrockspecimenswithbeddingplanesand correspondingsimulationsbycombinedfinite/discretenumericalmethod(FDEM)werecarriedout.The resultsshowthattheangleofbeddingplanehaveasignificantinfluenceonfracturepatternandtensile strengthofcoal.Itisclearthatastheangleofweakplaneincreases,thefracturepatternofmodelscan beclassifiedintofourtypes,includingstretchingfailureperpendiculartoweakbeddingplanes,complicatedsketchingandshearmixedpattern,shearfailurealongthebeddingplanes,andsketchingdamage alongweakbeddingplanes.Asforthedifferenceoftensilestrengthvalues,itisobservedthatwhenthe loadisperpendiculartothebeddingplane,theeffectofbeddingstructureoncalculatingtensilestrength isnegligibleandthetensilestrengthvaluedecreaseswiththeanglerisinguptotheminimumvalueas anglereachesvertical.Inaddition,withrespecttodissipatedenergyofcoalsamples,itisconcludedthat thedissipatedenergygraduallydecreaseswhentheangleofbeddingplanesareincreased,whichhavea relationshipwithvariedfracturepatternsandstrengthvalues.
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