The fracture of layered rocks subjected to tensile stress is involved in various subsurface energy-related activities. Many studies have numerically investigated the fracture evolution behaviour and Brazilian tensile strength (BTS) of layered rock in Brazilian tests. However, the fracture mechanism of layered rocks, especially those with interbedded hard-soft layers, is still not well understood. This is mainly due to the fact that the layered rocks were often modelled as two-phase materials only consisting of either rock matrix with layer interfaces or hard and soft layers without explicitly considering layer interfaces. In this study, rock-like discs interbedded with hard and soft layers are prepared with a dimension of 40 mm in diameter and 15 mm in thickness. The uniaxial compressive strength (UCS), BTS, and Young’s modulus of hard layers are 49 MPa, 6.7 MPa, and 10 GPa, respectively, while those of soft layers are 17 MPa, 3.2 MPa, and 8.0 GPa, respectively. The layered discs are tested with inclination angles between 0° and 90° at 15° interval under Brazilian tests with a loading rate of 0.24 mm/min. Then, three-dimensional layered models comprised of soft layers, hard layers, and layer interfaces are numerically established. Their mechanical behaviours are described by a newly developed constitutive model that can capture the tensile and compressive damage of rock-like materials under various loading scenarios. After validating against experimental results, the effects of Young’s modulus of layer interface and mechanical contrast of hard-to-soft layers on the stress distribution, crack initiation and propagation mechanisms, and peak load of layered discs with various inclination angles are numerically explored. It is observed that the effects of interface stiffness and mechanical contrast ratio on the peak load and fracture mechanism are layer orientation dependent.

受到拉应力的层状岩石的断裂涉及各种与地下能量相关的活动。许多研究对巴西试验中层状岩石的断裂演化行为和巴西抗拉强度（BTS）进行了数值研究。然而, 层状岩石的断裂机制, 特别是软硬层互层的岩石的断裂机制仍不清楚。这主要是因为层状岩石通常被建模为两相材料，仅由具有层界面的岩石基质或硬软层组成，而没有明确考虑层界面。在这项研究中，制备了直径为 40 毫米、厚度为 15 毫米的硬质和软质层互层的类岩石盘。单轴抗压强度 (UCS), BTS, 硬层的杨氏模量分别为49 MPa、6.7 MPa和10 GPa，而软层的杨氏模量分别为17 MPa、3.2 MPa和8.0 GPa。在巴西测试下，以 0.24 毫米/分钟的加载速率，以 0° 和 90° 之间的倾角以 15° 间隔对分层圆盘进行测试。然后，数值建立了由软层、硬层和层界面组成的三维分层模型。它们的力学行为由新开发的本构模型描述，该模型可以捕捉在各种载荷情况下类岩石材料的拉伸和压缩损伤。在对实验结果进行验证后，层界面的杨氏模量和硬到软层的机械对比对应力分布、裂纹萌生和扩展机制的影响，并对不同倾角的分层盘的峰值载荷进行了数值探索。据观察，界面刚度和机械对比度对峰值载荷和断裂机制的影响与层取向有关。