纤维增强混凝土三维细观建模方法研究

Study on 3D Mesoscale Modeling Methods for Fiber-Reinforced Concrete

摘要: 本研究针对纤维增强混凝土多相复合、细观结构复杂的特点，为提高其力学性能预测与机理分析的准确性，开展了三维细观建模方法研究。基于Python对Abaqus进行二次开发，实现了混凝土骨料、纤维、砂浆及界面过渡区的参数化生成与空间随机投放，建立了可反映材料真实三维细观结构的数值模型。开展了单轴压缩有限元模拟，结果表明，裂缝始于界面过渡区并逐渐向砂浆扩展，最终形成“V”形破坏形态，与试验现象一致；纤维应力分布具有显著的空间非均匀性，高应力纤维集中于裂缝路径，有效发挥桥接与增强作用。所建模型克服了二维简化的局限性，能够更真实模拟材料在三维空间中的损伤演化与破坏过程。

Abstract: This study focuses on the development of a three-dimensional mesoscale modeling method for fiber-reinforced concrete, addressing its multi-phase composition and complex mesostructure to enhance the accuracy of mechanical performance prediction and mechanistic analysis. Through secondary development of Abaqus using Python, parametric generation and spatial random distribution of concrete aggregates, fibers, mortar, and the interfacial transition zone were achieved, establishing a numerical model that reflects the true three-dimensional mesostructure of the material. Uniaxial compression finite element simulations were conducted, and the results indicate that cracks initiate in the interfacial transition zone and gradually propagate into the mortar, ultimately forming a “V”-shaped failure pattern consistent with experimental observations. The stress distribution in fibers exhibits significant spatial heterogeneity, with highly stressed fibers concentrated along the crack path, effectively contributing to bridging and reinforcement. The developed model overcomes the limitations of two-dimensional simplifications, enabling a more realistic simulation of damage evolution and failure processes in three-dimensional space.