基于临界距离点法的混凝土Ⅰ型断裂韧度的预测

混凝土的断裂韧度是极为重要的断裂力学材料参数，本文利用临界距离理论(TCD)中的点法和混凝土标准断裂梁试样裂缝尖端应力场的近似解，提出了一种对混凝土断裂问题按临界距离的点法进行分析的方法．基于已有文献的试验材料及其实验结果，分析了这种断裂研究分析方法的可行性．将临界距离点法与双K断裂准则应用于几何相似的混凝土梁的断裂韧性和断裂过程区分析，验证了TCD点法的可靠性．实验表明：临界距离理论的点法能够获得比双K断裂准则相对安全的失稳断裂韧度，利用临界距离法还可得到相应断裂过程区长度的极限估算值．

Prediction of Type I Fracture Toughness of Concrete Based on the Critical Distance Point Method

The fracture toughness is an extremely important material parameter for the fracture mechanics of concrete. In this paper, the point method in the critical distance theory (TCD) and the approximate solution of the stress field near the crack tip of the standard concrete fracture beam specimen are used to propose an approach to analyze the problem of concrete fracture based on the critical distance point method. The feasibility of this method for fracture analysis is evaluated using the test materials and the experimental results in the existing literature. The critical distance point method and the double-K fracture criterion are applied to the analysis of fracture toughness and the fracture process zone for the geometrically analogous concrete beams. The reliability of the TCD point method is verified. Experiments show that the point method of the critical distance theory can obtain a relatively safer unstable fracture toughness than the double-K fracture criterion, and can also be used to obtain the limit estimation of the size of the corresponding fracture process zone.