In order to study the effects of crack inclination angle and loading rate on rock mechanical properties, creep characteristics, and failure characteristics. Taking homogeneous red sandstone with different fracture angles as the research object, uniaxial compression tests and uniaxial compression creep tests were conducted at different loading rates. The results showed that under the same fracture angle, the loading rate was positively correlated with the peak strength, elastic modulus, instantaneous strain, creep strain, and steady-state creep rate of the sample, while negatively correlated with the peak strain. At the same loading rate, the mechanical properties and creep properties of the sample were controlled by the crack inclination angle α. With the increase of α, the peak strength, peak strain, instantaneous strain, creep strain and steady-state creep rate decreased first and then increased, and the elastic modulus increased. On the basis of rock creep testing, it is also important to establish a creep model that conforms to the actual test situation for studying rock creep characteristics. However, many models currently used cannot accurately describe the three stages of rock creep, especially the accelerated creep stage. Therefore, based on Burgers elements, this paper introduces plastic damage bodies based on damage rates and software components based on fractional calculus, A new creep model was obtained and its rationality was verified through experimental results. The results showed that the fit between the model and experimental data was above 0.97, indicating that the model can better describe the three stages of rock creep, especially reflecting the non-linear characteristics of the accelerated creep stage.

中文翻译：

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不同加载速率下含裂隙红砂岩力学性能试验研究


为了研究裂纹倾角和加载速率对岩石力学性能、蠕变特性和破坏特性的影响。以不同破裂角度​​的均质红砂岩为研究对象，进行了不同加载速率下的单轴压缩试验和单轴压缩蠕变试验。结果表明，在相同断裂角度下，加载速率与试样的峰值强度、弹性模量、瞬时应变、蠕变应变、稳态蠕变速率呈正相关，与峰值应变呈负相关。在相同加载速率下，试样的力学性能和蠕变性能由裂纹倾角α控制。随着α的增加，峰值强度、峰值应变、瞬时应变、蠕变应变和稳态蠕变速率先减小后增大，弹性模量增大。在岩石蠕变试验的基础上，建立符合试验实际情况的蠕变模型对于研究岩石蠕变特性也具有重要意义。然而，目前使用的许多模型无法准确描述岩石蠕变的三个阶段，特别是加速蠕变阶段。因此，本文在Burgers单元的基础上，引入基于损伤率的塑性损伤体和基于分数阶微积分的软件组件，得到了一种新的蠕变模型，并通过实验结果验证了其合理性。结果表明，模型与试验数据的拟合度在0.97以上，表明该模型能够较好地描述岩石蠕变的三个阶段，特别是反映加速蠕变阶段的非线性特征。