H Odé剪切变形理论在纳米尺度的表象  

Representation of H Odé Shear Deformation Theory at Nanoscale

作　　者：孙岩[1] 琚宜文 黄骋 周巍[1] 晁洪太[3] 王志才[3] Sun Yan;Ju Yiwen;Huang Cheng;Zhou Wei;Chao Hongtai;Wang Zhicai(School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China;College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;Earthquake Administration of Shandong Province, Jinan 250014, China)

机构地区：[1]南京大学地球科学与工程学院,江苏南京210093 [2]中国科学院大学地球与行星科学学院,北京100049 [3]山东省地震局,山东济南250014

出　　处：《地球科学》2018年第5期1518-1523,共6页Earth Science

基　　金：国家自然科学基金项目(Nos.41530315;41372213);国家重点基础研究计划(973计划)项目(No.2012CB416706);山东省科学基金项目(No.ZR2012DM005)

摘　　要：通常认为岩石是被剪破或张裂的,那么,为何我们能寻觅到位于同压力垂直方向的破裂构造呢?H Odé剪切变形理论给出一个精辟的回答:在塑性或粘-弹性变形中,由于介质的分异作用,存在一个从屈服条件中获得的速度不连续性,这样,其介质就能沿着等速的特征面剪切滑移.该理论亦称为塑性剪切作用准则,之前是从宏观-直观力学表象予以验证,如构造挤压带的破裂面、正压力下Griffith裂隙端点裂开和垂直压力下的碎裂流动等.进而,我们对花岗岩标本实施高温/高压实验,并取其位于轴压垂直方向裂隙的薄壳表层做扫描电镜观测.然后把从其表层观察的具有H Odé力学表象的微纳米现象,同一般剪切作用的屈服效应结构,从3个方面相比较鉴别.(1)粘-弹性变形:高温-高压的实验样品更容易产生塑性压缩容积流动,不仅具粘性也具弹性变形,随之,样品可展现纳米涂层作用和纳米分层作用.(2)纳米尺度结构:纳米尺度颗粒能成为单一纳米粒-纳米线-纳米层结构,且复体的纳米粒可细分成粒状的、线状的和片粒状的结构等.(3)有序组构:尽管H Odé破裂的粒化流动和纹理流动的优选方位,同普通剪切作用相比,处于弱势范畴,然而综合分析观之,这两者的屈服特征是完全一致的.反之,我们应用H Odé剪切理论去研究一些非常规的变形现象,必能拓展纳米地质学的研讨范畴和认知能力.Generally speaking,a rock is broken by shearing action or tensile force,in that case,why can we find some fracture structures perpendicular to the pressure direction？It can be solved through H Odé shear deformation theory.In plastic（or viscous-elastic）deformation,there is a velocity discontinuity which may be gained from a yield condition due to a medium differentiation,and thus the medium can just shear slip along the characteristic planes with an equal velocity.This theory is also called the plastic shearing criteria,and it was firstly verified from a macroscopic-mesoscopic mechanics representation,including the fracture planes in compressive zone,extreme point rupture of Griffith crack under normal press,and cataclastic flow in vertical pressure.Furthermore,high temperature and high pressure（HT/HP）experiment to granite samples was carried out,and the thin shells of crack surfaces,which are perpendicular to the axle load,were taken for the SEM determination.Then the micro/nanosized phenomena observed in crack surfaces with H Odé mechanics representation are compared with the textures of general shearing yield function from three aspects.（1）Viscous-elastic deformation：the experimental specimens passed HT/HP are more likely to produce a plastic compactive volumetric flow,invloving not only viscous deformation but also elas-tic one.Consequently,the specimens can exhibit effects of nano-coating and nano-layering.（2）Nanosized texture：nanosized grain（with diameter 60-80 nm）can turn into single nanoparticle-nanoline-nanolayer texture,and aggregate grains may be subdivided into granular,linear granular and schistose granular textures,etc.（3）Ordered fabrication：though preferred orientations of the granular flow and streak flow in H Odé shear fractures belong to a weaker scale than common shearing,their yield characteristics are entirely corresponding with the latter from comprehensive analysis.It is suggested that H Odé shear theory can be applied to research some few unconventional d

关 键 词：H Odé剪切变形 纳米尺度 粘-弹性变形 三轴压力实验 有序组构 构造地质 

分 类 号：P54[天文地球—构造地质学]