In recent years, HRB400 and HTRB600 steel bars have become the mainstream standard reinforcing steel used in concrete structures in China. However, significant controversy still exists regarding the selection of material constitutive models and the determination of model parameters for buckling, fatigue, hysteresis, and other material characteristics. In this article, an automated process of multi-parameter calculation of the constitutive model for reinforcing steel – simulation accuracy evaluation of the constitutive model – selection of the constitutive model of reinforcing steel is established based on the hybrid programming method using MATLAB and OpenSees software. First, tensile and low-cycle fatigue tests were carried out on HRB400 and HTRB600 steel bars. Second, based on the constitutive model in OpenSees software and the skeleton curve and characteristics such as yielding, fatigue, and hysteresis, the constitutive model parameters of HRB400 and HTRB600 steel bars are determined using indirect and direct fitting methods. Finally, the five similarity parameters of the simulated normalized cumulative hysteretic energy dissipation coefficient are compared with the test results. The results indicate that the simulation accuracy of the Reinforcing Steel model exceeds 72%, which is higher than other four models, making it the best choice for reinforcing steel in numerical simulation.

中文翻译：

---

基于拉伸和疲劳试验的HRB400和HTRB600钢筋本构模型参数数值研究

近年来，HRB400和HTRB600钢筋已成为我国混凝土结构使用的主流标准钢筋。然而，在材料本构模型的选择以及屈曲、疲劳、滞后和其他材料特性的模型参数的确定方面仍然存在重大争议。本文利用MATLAB和OpenSees软件，基于混合编程方法，建立了钢筋本构模型多参数计算-本构模型仿真精度评价-钢筋本构模型选择的自动化流程。首先，对HRB400和HTRB600钢筋进行拉伸和低周疲劳试验。其次，根据OpenSees软件中的本构模型，结合骨架曲线和屈服、疲劳、滞后等特性，采用间接和直接拟合方法确定HRB400和HTRB600钢筋的本构模型参数。最后，将模拟的归一化累积滞回耗能系数的五个相似参数与试验结果进行比较。结果表明，钢筋模型的模拟精度超过72%，高于其他四个模型，使其成为数值模拟中钢筋的最佳选择。