The tensile creep fracture behaviors in brittle solids are of great significance for the safety evaluation of brittle solid engineering. However, micromechanics-based tensile creep fracture behavior is rarely studied. In this study, a micromechanics-based method for predicting direct tensile creep fractures is presented. This method is established by combining the suggested expression of the mode-I stress intensity factor, the subcritical crack growth law, and the relationship between wing crack length and axial strain. This suggested mode-I stress intensity factor is formulated by the use of the basic theory of fracture mechanics under different loading modes. The rationality of the proposed tensile creep fracture model is verified by comparing with the experimental results. The correspondences of time-dependent axial strain, strain rate, wing crack length, and crack velocity are plotted under constant stress and stepping stress during tensile creep fracture. The effects of the initial crack size, inclination angle and density on the crack initiation stress, tensile strength, tensile creep fracture time, steady-state strain rate, initial strain, crack coalescence strain, and failure strain are discussed.

脆性固体的拉伸蠕变断裂行为对脆性固体工程的安全性评价具有重要意义。然而，很少研究基于微观力学的拉伸蠕变断裂行为。在这项研究中，提出了一种基于微观力学的预测直接拉伸蠕变断裂的方法。该方法是通过结合I型应力强度因子的建议表达式、亚临界裂纹扩展规律以及翼裂纹长度与轴向应变之间的关系建立的。该建议的 I 型应力强度因子是通过使用不同加载模式下的断裂力学基本理论制定的。通过与实验结果的对比验证了所提出的拉伸蠕变断裂模型的合理性。瞬态轴向应变、应变率、翼裂纹长度和裂纹速度在拉伸蠕变断裂过程中在恒定应力和步进应力下绘制。讨论了初始裂纹尺寸、倾角和密度对裂纹起始应力、拉伸强度、拉伸蠕变断裂时间、稳态应变率、初始应变、裂纹合并应变和破坏应变的影响。