Abstract

Platy structures are a common geological feature in nature, and rock masses are often subjected to dynamic loadings. However, the dynamic behavior of rock plates has rarely been investigated. Three-dimensional FEM-based numerical modeling is used in this study to understand the cracking and failure characteristic of rock plates subjected to impact loading. First, a numerical plate center impact testing system is established. The impact is simulated by hitting the center of a rock plate with a striker. The rock plate model has a high width-to-thickness ratio, and its heterogeneity is described by the Weibull distribution function for specific physical parameters. During impact, the contact between the striker and the plate is captured by a three-dimensional dynamic contact model, and the damage evolution in the rock plate is analyzed using the equivalent damage method. After comparison with laboratory measurements, the applicability of the proposed numerical method in modeling the cracking and failure characteristics of a rock plate under impact loading is validated. The simulation results indicate that radial cracks first initiate at the center of the rear surface of the rock plate, and these cracks propagate to the boundaries and penetrate to the front surface of the rock plate. The number of radial cracks is dependent on the rock plate thickness: the number of radial cracks decreases with increasing rock plate thickness. In addition, circular cracks are induced when the impact velocity is sufficiently high or the rock plate thickness is sufficiently small. Two types of circular cracks are identified and classified by the initiation time and mechanism. The findings in this study may facilitate a comprehensive understanding of the failure process of rock plates under impact loading.

Highlights

• A novel three-dimensional dynamic contact method for simulating the contact process is proposed;

• Cracking of a rock plate under center impact loading is analyzed;

• Mechanisms of the failure behaviors of the rock plate under center impact loading are revealed.

中文翻译：

---

冲击载荷作用下岩板开裂与破裂的三维数值研究

摘要

板状结构是自然界中常见的地质特征，并且岩体经常承受动态载荷。然而，很少研究岩石板的动力学行为。在这项研究中使用基于三维有限元的数值模型来了解冲击载荷作用下岩石板的开裂和破坏特征。首先，建立了数值板中心冲击测试系统。通过用撞针撞击岩石板的中心来模拟冲击。岩石板模型具有高的宽厚比，其异质性由特定物理参数的Weibull分布函数描述。在撞击过程中，撞针与板之间的接触通过三维动态接触模型捕获，并利用等效损伤法分析了岩盘中的损伤演化。在与实验室测量结果进行比较之后，验证了所提出的数值方法在冲击载荷作用下对岩石板的破裂和破坏特性进行建模的适用性。仿真结果表明，径向裂纹首先在岩石板后表面的中心开始，然后这些裂纹扩展到边界并渗透到岩石板的前表面。径向裂纹的数量取决于岩石板的厚度：径向裂纹的数量随着岩石板厚度的增加而减少。另外，当冲击速度足够高或岩石板厚度足够小时，会引起圆形裂纹。根据引发时间和机理，可以识别和分类两种类型的圆形裂纹。这项研究的结果可能有助于全面了解冲击载荷作用下岩石板的破坏过程。

强调

• 提出了一种新型的模拟接触过程的三维动态接触方法。

• 分析了中心冲击载荷作用下岩石板的开裂；

• 揭示了岩石板在中心冲击载荷作用下的破坏行为机理。