It is widely recognized that steel fibres exhibit directional distribution during the preparation of 3D-printed steel fibre reinforced concrete (SFRC). The degree of fibre orientation varies due to several factors, such as nozzle size and layer height. This variation in fibre orientation range may result in different mechanical performance exhibited by 3D-printed SFRC at hardened state. To explore the relationship between steel fibre orientation and the mechanical properties of 3D-printed SFRC at hardened state, this study firstly establishes three-dimensional mesoscale finite element models based on the distribution of fibres in 3D-printed SFRC. The steel fibre and matrix work together through a mechanism for fluid-structure interaction between models. Then, compares the simulation results with experimental data to verify the accuracy of the models. After that, different steel fibre distribution orientations were set, and parametric analysis was conducted for the compressive and tensile loading conditions to explore the effects of fibre orientation on the damage mode and strength of 3D-printed SFRC. The results indicate that 3D-printed SFRC exhibits different damage modes with varying steel fibre orientation ranges. Additionally, the strength of 3D-printed SFRC varies in steel fibre orientation range and exhibits anisotropic characteristics. This study provides a theoretical basis for improving and controlling the performance of 3D-printed SFRC in future engineering applications.

中文翻译：

---

不同取向钢纤维对3D打印钢纤维混凝土力学性能的影响：细观有限元分析

人们普遍认为，在3D打印钢纤维混凝土（SFRC）的制备过程中，钢纤维表现出定向分布。纤维取向程度因多种因素而异，例如喷嘴尺寸和层高。纤维取向范围的​​这种变化可能会导致 3D 打印的 SFRC 在硬化状态下表现出不同的机械性能。为了探讨硬化状态下钢纤维取向与3D打印钢纤维混凝土力学性能之间的关系，本研究首先基于3D打印钢纤维混凝土中纤维的分布建立了三维细观有限元模型。钢纤维和基体通过模型之间的流固相互作用机制协同工作。然后，将仿真结果与实验数据进行比较，验证模型的准确性。之后，设置不同的钢纤维分布方向，并对压缩和拉伸加载条件进行参数分析，探讨纤维方向对3D打印钢纤维混凝土损伤模式和强度的影响。结果表明，3D 打印的 SFRC 表现出不同的损伤模式和不同的钢纤维取向范围。此外，3D打印的SFRC的强度在钢纤维取向范围内变化，并表现出各向异性特征。该研究为未来工程应用中改善和控制3D打印钢纤维混凝土的性能提供了理论依据。