In this study, several simplified constitutive models and a damage plasticity model for ultra-high performance fiber reinforced concrete(UHPFRC)material with micro and hooked ends steel fibers, Bekaert Dramix 5D steel fiber, and Forta-Ferro synthetic fiber had been developed. Later, these constitutive and damage plasticity models were applied as analytical model to numerically simulate the concrete members with different fibers, and to evaluate the behavior of the concrete sections. The constitutive models for UHPFRC of three mix designs were obtained experimentally by conducting uniaxial compression and tensile tests on both cylinder and dog-bone specimens. Next, a comparison was made among the three mix designs based on the outcomes retrieved from uniaxial compression and tensile stress–strain. These results were validated by numerically analyzing three hollow circular columns via finite element method. The numerical results revealed that the proposed material model possessed appropriate tensile strain-hardening behavior and uniaxial compression strengths of UHPFRC with different types of fiber. The lateral resistance responses of the tested hollow sections, which were obtained by using developed constitutive and damage plasticity models, displayed exceptional agreement with the experimental outcomes.

中文翻译：

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具有不同类型纤维的 UHPFRC 的简化本构和损伤塑性模型

在这项研究中，开发了几种简化的本构模型和超高性能纤维增强混凝土 (UHPFRC) 材料的损伤塑性模型，该材料具有微型和钩端钢纤维、Bekaert Dramix 5D 钢纤维和 Forta-Ferro 合成纤维。后来，这些本构模型和损伤​​塑性模型被用作分析模型，对不同纤维的混凝土构件进行数值模拟，并评估混凝土截面的行为。通过对圆柱和狗骨试样进行单轴压缩和拉伸试验，通过实验获得了三种混合设计的 UHPFRC 本构模型。接下来，根据从单轴压缩和拉伸应力-应变中检索到的结果，对三种混合设计进行了比较。通过有限元方法对三个空心圆柱进行数值分析，验证了这些结果。数值结果表明，所提出的材料模型具有适当的拉伸应变硬化行为和不同类型纤维的 UHPFRC 的单轴压缩强度。通过使用开发的本构模型和损伤​​塑性模型获得的测试空心截面的横向阻力响应与实验结果非常吻合。