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| 含裂隙岩石动态力学性质及破坏模式尺寸效应研究 |
| Study on the dynamic mechanical properties and size effect of failure modes of fractured rocks |
| 投稿时间：2024-12-12 修订日期：2025-04-15 |
| DOI： |
| 中文关键词: 含裂隙岩石 尺寸效应 力学性质 破坏模式 SHPB系统 |
| 英文关键词:fractured rock size effect mechanical properties destructive mode SHPB system |
| 基金项目:国家自然科学基金(U23A2068) |
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| 摘要点击次数: 409 |
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| 中文摘要: |
| 为探究含裂隙岩石动态力学性质及破坏模式尺寸效应,以不同尺寸含预制裂隙类岩石试样为研究对象,通过相同冲击强度的SHPB试验,得到试样尺寸效应、应变率效应的关联性及关联程度,在多组验证性SHPB试验的基础上,获得相同应变率条件下的不同尺寸试样力学性质及破坏模式特征。研究结果表明,尺寸效应和应变率效应对试样的动态强度产生耦合影响。相同应变率条件下,试样动态强度随尺寸的增大呈增加趋势,与相同冲击强度试验结果相比,控制应变率相同会明显减弱预制裂隙倾角对动态强度的影响。相同应变率下,试样首条新生裂纹一般在预制裂隙端部萌生,本文应变率条件下,随试样尺寸增大试样裂纹种类由拉伸、剪切及混合型裂纹向以拉伸裂纹为主转变。试样破碎块度与裂纹扩展类别有关,试样平均破碎块度是随试样尺寸变化的敏感变量,随试样尺寸的增加,试样碎块分形维数逐渐增加,不同预制裂纹倾角对分形维数的影响不同,这与试样裂纹类型及数量关系密切。 |
| 英文摘要: |
| To investigate the dynamic mechanical properties and failure mode size effects of fractured rocks, different sizes of pre fabricated fractured rock samples were taken as the research objects. Through SHPB tests with the same impact strength, the correlation and degree of correlation between sample size effects and strain rate effects were obtained. Based on multiple sets of confirmatory SHPB tests, the mechanical properties and failure mode characteristics of different size samples under the same strain rate conditions were obtained. The research results indicate that the size effect and strain rate effect have a coupled effect on the dynamic strength of the specimen. Under the same strain rate conditions, the dynamic strength of the specimen increases with the increase of size. Compared with the results of the same impact strength test, controlling the same strain rate will significantly weaken the influence of the pre fabricated crack inclination angle on the dynamic strength. Under the same strain rate, the first newly formed crack in the specimen generally initiates at the end of the pre-existing crack. In this study, under the strain rate conditions, as the specimen size increases, the types of cracks in the specimen change from tensile, shear, and mixed cracks to mainly tensile cracks. The fragmentation degree of the sample is related to the type of crack propagation. The average fragmentation degree of the sample is a sensitive variable that varies with the size of the sample. As the size of the sample increases, the fractal dimension of the sample fragments gradually increases. Different pre fabricated crack angles have different effects on the fractal dimension, which is closely related to the type and quantity of cracks in the sample. |
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