单轴压缩下岩石动态细观损伤本构模型
发布时间：2019-01-10 12:03
【摘要】：目前岩石动态损伤本构模型未能很好地同时考虑临界应变及已有损伤对被激活微裂纹数目的影响,为此,基于微裂纹在单轴压缩荷载下的扩展机理,提出了新的岩石单轴压缩动态损伤本构模型。在假定岩石中被激活的微裂纹数服从Weibull分布的基础上,首先,通过临界应变对被激活微裂纹数目的影响,建立了考虑临界应变及微裂纹扩展长度的单轴压缩损伤本构关系;其次,根据微裂纹在单轴压缩下的翼裂纹扩展方程,考虑翼裂纹扩展过程中的惯性效应及翼裂纹扩展速度与应变率之间的关系,建立了单轴压缩下岩石动态细观损伤本构模型。最后采用数值算例对模型的合理性进行了验证。结果表明:随着Weibull分布参数k和m的增加,岩石动态抗压峰值强度分布减小和增加,且m的影响更为显著。随着微裂纹摩擦系数、岩石断裂韧性和应变率的增加,岩石动态抗压峰值强度增加;而随着微裂纹长度的增加,岩石动态峰值强度则降低。该结论与目前的研究成果较为一致,说明了该模型的合理性。
[Abstract]:At present, the dynamic damage constitutive model of rock fails to take into account both the critical strain and the effect of existing damage on the number of activated microcracks. Therefore, based on the propagation mechanism of microcracks under uniaxial compression load, A new dynamic damage constitutive model of rock under uniaxial compression is proposed. Based on the assumption that the number of activated microcracks in rock is distributed from Weibull, the uniaxial compression damage constitutive relation considering critical strain and microcrack propagation length is established through the influence of critical strain on the number of activated microcracks. Secondly, according to the wing crack propagation equation under uniaxial compression, considering the inertia effect during the crack growth and the relationship between the crack growth velocity and strain rate, the dynamic meso-damage constitutive model of rock under uniaxial compression is established. Finally, a numerical example is used to verify the rationality of the model. The results show that the peak strength distribution of rock dynamic compression decreases and increases with the increase of Weibull distribution parameters k and m, and the effect of m is more significant. With the increase of the friction coefficient of microcracks, the fracture toughness and strain rate of rock, the dynamic compressive peak strength of rock increases, while the dynamic peak strength of rock decreases with the increase of microcrack length. The conclusion is consistent with the current research results, which shows the rationality of the model.
【作者单位】： 黄淮学院建筑工程学院;中国地质大学(北京)工程技术学院;
【基金】：中央高校基本科研业务费专项资金项目(2652014019;2652015263) 国家自然科学基金项目(41162009)
【分类号】：TU45
[Abstract]:At present, the dynamic damage constitutive model of rock fails to take into account both the critical strain and the effect of existing damage on the number of activated microcracks. Therefore, based on the propagation mechanism of microcracks under uniaxial compression load, A new dynamic damage constitutive model of rock under uniaxial compression is proposed. Based on the assumption that the number of activated microcracks in rock is distributed from Weibull, the uniaxial compression damage constitutive relation considering critical strain and microcrack propagation length is established through the influence of critical strain on the number of activated microcracks. Secondly, according to the wing crack propagation equation under uniaxial compression, considering the inertia effect during the crack growth and the relationship between the crack growth velocity and strain rate, the dynamic meso-damage constitutive model of rock under uniaxial compression is established. Finally, a numerical example is used to verify the rationality of the model. The results show that the peak strength distribution of rock dynamic compression decreases and increases with the increase of Weibull distribution parameters k and m, and the effect of m is more significant. With the increase of the friction coefficient of microcracks, the fracture toughness and strain rate of rock, the dynamic compressive peak strength of rock increases, while the dynamic peak strength of rock decreases with the increase of microcrack length. The conclusion is consistent with the current research results, which shows the rationality of the model.
【作者单位】： 黄淮学院建筑工程学院;中国地质大学(北京)工程技术学院;
【基金】：中央高校基本科研业务费专项资金项目(2652014019;2652015263) 国家自然科学基金项目(41162009)
【分类号】：TU45
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