This paper presents a finite element (FE) analysis for predicting the flexural behavior of reinforced concrete (RC) beams strengthened with Fe-based shape memory alloy (Fe-SMA) strips using a near surface mounted (NSM) method. Experimental results reported in the literature were used to verify the proposed FE model. FE analyses were conducted using OpenSees, a general-purpose structural FE analysis program. The RC beam specimens were modeled using a nonlinear beam-column element and a fiber element. The Concrete 02 model, Steel 01 model, and Pinching 04 model were applied to the concrete, steel reinforcement, and Fe-SMA strip in the fiber element, respectively, and the FE analysis was carried out in a displacement control method based on the Newton-Raphson method. The FE model of this study accurately predicted the initial crack load, yield load, and ultimate load. From parametric analyses, it was concluded that an increase in the compressive strength of the concrete increases the ductility of the specimen, and an increase in the level of recovery stress on the Fe-SMA strip increases the initial stiffness of the specimen.

中文翻译：

---

铁基形状记忆合金带材加固钢筋混凝土梁的 NSM 数值研究

本文提出了一种有限元 (FE) 分析，用于使用近表面安装 (NSM) 方法预测用铁基形状记忆合金 (Fe-SMA) 条加固的钢筋混凝土 (RC) 梁的弯曲行为。文献中报告的实验结果用于验证所提出的有限元模型。有限元分析是使用通用结构有限元分析程序 OpenSees 进行的。RC 梁试样使用非线性梁柱单元和纤维单元建模。混凝土02模型、钢01模型和Pinching 04模型分别应用于混凝土、钢筋和纤维单元中的Fe-SMA条，并以基于牛顿位移控制方法进行有限元分析-拉夫森方法。本研究的有限元模型准确预测了初始裂纹载荷、屈服载荷、和极限载荷。参数分析得出的结论是，混凝土抗压强度的增加会增加试件的延展性，而 Fe-SMA 条上恢复应力水平的增加会增加试件的初始刚度。