Many fracture models have data-fitting parameter(s). In this paper, an explicit probabilistic fracture model was proposed by considering microstructure, plastic limit and size effect. Normal distribution with fixed mean and standard deviation was incorporated to characterize inevitable scatter of fracture strength from material heterogeneity and machining errors. The fracture measurements on concretes (aggregate size d_max: 5.25–21 mm) and mortar under different loadings were used to validate proposed model, and found predicted curves could cover all experimental data. The results indicate that proposed model could predict facture of quasi-brittle materials with different d_max and under different loading ways.

许多裂缝模型具有数据拟合参数。在本文中，考虑了微观结构，塑性极限和尺寸效应，提出了一个明确的概率断裂模型。合并具有固定均值和标准偏差的正态分布，以表征由于材料异质性和加工误差而导致的断裂强度不可避免的分散。用混凝土（骨料的_最大尺寸d _max：5.25-21 mm）和砂浆在不同载荷下的断裂测量结果来验证所提出的模型，发现预测的曲线可以覆盖所有实验数据。结果表明，所提出的模型可以预测不同d _max和不同加载方式下的准脆性材料的屈服。