冲击载荷下深部细砂岩的力学性能试验研究

发布时间：2018-04-15 17:04

本文选题：深部细砂岩 + 动态力学性能　；参考：《河南理工大学》2015年硕士论文

【摘要】：深部岩体由于其复杂的受力环境,并且经常遭受冲击载荷,因此其力学性能与浅部岩石显著差异。因此,研究冲击载荷下深部岩石的力学性能十分必要。本文采用万能材料试验机和分离式Hopkinson(SHPB)试验装置,进行深部细砂岩在准静态及动态载荷下的单轴压缩和劈裂拉伸试验,研究在不同应变率、不同含水状态及不同温度因素影响下深部细砂岩的力学响应,并分析试样的破坏模式。同时采用高速摄影机和超高速摄影机记录试样的变形破坏,并使用数字图像相关(DIC)方法分析其应变分布。采用ANSYS/LS-DYNA数值模拟典型的SHPB实验,再现试样的变形和破坏过程。常温下,随着应变率的增加,深部细砂岩的抗压强度和抗拉强度均逐渐增大,然而,当应变率增大至一定程度时,其增幅减缓。尽管应变率对破坏模式影响较大,但对断裂应变影响不显著。在应变率相同的常温条件下,天然状态下的细砂岩的抗压强度和抗拉强度明显大于饱水状态,然而,深部细砂岩的含水状态仅对破坏应变及破坏模式影响较小;在单轴压缩实验中饱水状态下的破坏应变略大。天然状态的细砂岩的抗压强度随实验温度的升高而降低,而抗拉强度则随温度的升高而增加;然温度的变化对其破坏模式影响不显著。高速摄影记录的深部细砂岩试件在准静态、动态压缩、劈裂试验的破坏过程,裂纹由出现到贯通、直至试样破坏的各个阶段中,不同的含水状态、不同的应变率所产生的影响程度均有差别。
[Abstract]:The mechanical properties of deep rock mass are obviously different from those of shallow rock because of its complex stress environment and often subjected to impact load.Therefore, it is necessary to study the mechanical properties of deep rock under impact loading.In this paper, uniaxial compression and splitting tensile tests of deep fine sandstone under quasi static and dynamic loads are carried out by means of universal material testing machine and split Hopkinsonian SHPB test device, and the strain rates at different strain rates are studied.The mechanical response of deep fine sandstone is affected by different water-bearing states and different temperature factors, and the failure mode of the specimen is analyzed.At the same time, high speed camera and super high speed camera are used to record the deformation and failure of the sample, and the strain distribution of the specimen is analyzed by digital image correlation (DIC) method.The typical SHPB experiment was simulated by ANSYS/LS-DYNA to reproduce the deformation and failure process of the specimen.At room temperature, the compressive strength and tensile strength of deep fine sandstone gradually increase with the increase of strain rate, however, the increase of strain rate slows down when the strain rate increases to a certain extent.Although strain rate has great influence on failure mode, it has no significant effect on fracture strain.Under the same strain rate at room temperature, the compressive strength and tensile strength of natural fine sandstone are obviously higher than that of saturated state, however, the water content of deep fine sandstone has little effect on the failure strain and failure mode.In uniaxial compression test, the failure strain is slightly larger under saturated state.The compressive strength of natural fine sandstone decreases with the increase of experimental temperature, while the tensile strength increases with the increase of temperature, but the change of temperature has no significant effect on its failure mode.In the failure process of quasi-static, dynamic compression and splitting tests, the cracks in the deep fine sandstone specimens recorded by high-speed photography are changed from appearing to through to different water-bearing states in various stages of specimen failure.The degree of influence of different strain rate is different.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45

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