Abstract

This paper deals with a mesomechanical modeling of fracture in concrete like quasi-brittle materials. The paper seeks to provide insight regarding the variation of the fracture process zone (FPZ) length during the cracking process. The correlation between the FPZ length and the crack extension is also investigated. The FPZ variation is investigated through the evolution of cohesive tangential stresses along the crack path of different notched beams under three-point bending tests. The concept of equivalent linear elastic fracture mechanics is then employed to compute the crack extensions. The mesoscale investigation shows that the relationship between the FPZ length and the crack length is non linear. Furthermore, the numerical crack extensions are used to investigate the R-curve. It is shown that the R-curve is size-dependent and notch-sensitive.

中文翻译：

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混凝土断裂过程带长度与裂纹扩展关系的细观力学研究

摘要

本文涉及准脆性材料等混凝土断裂的细观力学模型。本文旨在提供有关裂化过程中断裂过程区（FPZ）长度变化的见解。还研究了FPZ长度与裂纹扩展之间的相关性。通过在三点弯曲试验下沿着不同缺口梁的裂纹路径的内向切应力的演变来研究FPZ的变化。然后采用等效线性弹性断裂力学的概念来计算裂纹扩展。中尺度研究表明，FPZ长度和裂纹长度之间的关系是非线性的。此外，数值裂纹扩展用于研究R曲线。结果表明，R曲线与尺寸有关且对缺口敏感。