动力扰动下含泥体孔道花岗岩试件力学特性研究

发布时间：2018-04-13 14:32

本文选题：花岗岩 + 力学特性　；参考：《湖南科技大学》2017年硕士论文

【摘要】：本文以SHPB动态测试系统为平台,以花岗岩为研究对象。对不同内孔径花岗岩试件在填充不同含水率泥体的状态下进行冲击对比实验。分析了应力-应变曲线、破坏过程、破坏模式、岩石吸能特性对花岗岩动力特性的影响。进行了填充不同含水率泥体花岗岩在单次冲击荷载作用下的试验研究。运用高速摄像技术,将微裂纹的发育、拓展与贯通对比分析花岗岩破坏的实验现象。结合破坏图片,通过能量比法分析了花岗岩破坏时的能量对比。主要研究内容与成果如下:(1)相同应变率下,随着试件内孔径的增大,峰值应力减小;随着泥浆含水率的增加,峰值应力增大,应力-应变曲线峰后塑性现象逐渐增强。(2)岩石的破坏过程中,泥浆与内孔径对试件破坏模式相关性小。结果表明首先出现斜向剪切裂纹和纵向裂纹,最后出现横向裂纹且拉应力破坏占据主要破坏方式。(3)通过能量破坏准则分析,得到内孔径越大,反射能比越小,透射能比越大,花岗岩破碎程度越高,其耗散能比越大。用单位体积吸能比大小来衡量试件的破碎效果具有可行性。(4)花岗岩内部裂纹的发育受冲击荷载和水压力共同作用的影响,裂纹的拉剪和压剪扩展模式下控制着花岗岩的破坏过程和破坏模式。
[Abstract]:This paper takes the SHPB dynamic test system as the platform and the granite as the research object.A comparative impact test of granite specimens with different internal pore sizes was carried out under the condition of filling mud with different moisture content.The influences of stress-strain curve, failure process, failure mode and rock energy absorption characteristics on the dynamic characteristics of granite are analyzed.An experimental study of marsh granite filled with different moisture content under single impact load was carried out.The development of microcracks and the experimental phenomena of granite failure are compared and analyzed by using high speed camera technique.Combined with the damage picture, the energy comparison of granite failure was analyzed by energy ratio method.The main research contents and results are as follows: at the same strain rate, the peak stress decreases with the increase of the pore diameter of the specimen, and the peak stress increases with the increase of the water content of the mud.During the failure process of rock, the correlation between mud and internal pore size on the failure mode of specimen is small.The results show that the inclined shear crack and longitudinal crack appear first, and finally the transverse crack and tensile stress failure occupy the main failure mode. Through the energy failure criterion analysis, the larger the internal aperture, the smaller the reflection energy ratio and the greater the transmission energy ratio.The higher the degree of granite fragmentation, the greater the dissipation energy ratio.It is feasible to use the unit volume energy absorption ratio to measure the breakage effect of the specimen. (4) the development of internal cracks in granite is affected by the combined action of impact load and water pressure.The failure process and failure mode of granite are controlled by the tensile shear and compression shear propagation modes of cracks.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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