Study on the failure process of rocks with closed fractures under compressive loading using improved bond-based peridynamics
Study on the failure process of rocks with closed fractures under compressive loading using improved bond-based peridynamics
复制标题
利用改进的基于粘结的近场动力学研究压缩载荷下闭合裂隙岩石的破坏过程
DOI：
10.1016/j.engfracmech.2020.107315
复制
发表时间：
2020-12-01
影响因子：
5.4
通讯作者：
Zhang, Zhenping
中科院分区：
文献类型：
--
作者：
Du, Wenjie;Fu, Xiaodong;Zhang, Zhenping
由于传统的基于粘结的周动力理论（BBPD）中粘结破坏准则的一致性，岩石在拉伸和压缩载荷作用下的裂纹扩展模式几乎相同，但在实际中，拉伸和压缩状态下的断裂机制完全不同。为了解决这一问题，在传统的BB-PD基础上进行了两次扩展，形成了改进的基于键的周动力学理论（iBB-PD）。首先，提出了一种考虑岩体裂隙实际闭合状态的裂隙建模方法，该方法可以在闭合裂隙中传递应力或波；其次，通过引入弹脆塑性本构模型，将传统的PMB模型扩展到模拟压缩条件下的粘结破坏；本文给出了三个基准示例来说明iBB-PD的基本原理。采用iBB-PD理论对单轴压缩条件下存在闭合裂缝的岩石试样进行了裂纹萌生、扩展和聚并模拟，数值结果与实验结果吻合较好。本文提出的iBB-PD方法可以扩展传统的周动力学来捕捉岩石在压剪应力条件下的破坏过程。
Since the consistency of the bond failure criterion in traditional bond-based peridynamics (BBPD) theory, the crack-propagation pattern of rocks under tensile and compressive loads is almost the same, however in reality the mechanisms of fractures in tensile and compression state are totally different. To solve this problem, two extensions are conducted on the basis of the traditional BB-PD to form the improved bond-based peridynamics theory (iBB-PD). First, a novel fracture-modeling method considering the actual closed state of fractures in a rock mass is proposed, which can transfer stress or waves across closed fractures. Second, by introducing the elastic-brittle-plastic constitutive model, the traditional PMB model is extended to simulate bond failure under compressive conditions. Three benchmark examples are presented to illustrate the rationale of iBB-PD. The iBB-PD theory is used to simulate the crack initiation, propagation and coalescence in rock specimens with pre-existing closed fractures under uniaxial compression, and the numerical results are in good agreement with the experimental results. The iBB-PD method proposed in this paper could extend traditional peridynamics to capture the failure process of rocks under compressive-shear stress conditions.