## 5 Conclusions  
In this study, a FE model was proposed for predicting the flexural behavior of RC beams strengthened with Fe-SMA strips using the NSM method. The reliability of this model was verified with experimental results reported in the literatures. Then, parameter analyses were conducted to determine which variable affected the flexural behavior of RC beams strengthened with Fe-SMA. The conclusions of this study are as follows:  
1. The ratios of the numerical results to experimental results in terms of the initial crack load, yield load, and ultimate load were an average of 1.04, 1.01, and 1.01, respectively, and the standard deviations were 0.09, 0.03, and 0.07, respectively. It can be concluded that the proposed FE models accurately predicted the RC beams strengthened with the Fe-SMA strips using the NSM method.
2. The initial crack load, yield load, and ultimate load of the RC beam strengthened with Fe-SMA strip using the NSM method, when the compressive strength of concrete increased from 21 MPa to 35 MPa, increased by 8.98%, 1.72%, and 10.06%, respectively.  
\begin{table}
\begin{tabular}{c} **Ultimate Load** \\ **(km)** \\ \end{tabular} \\ \hline
142.6 & 7.05 & 19.11 & 24.22 & 16.07 & 32.15 & 45.03 \\
285.2 & 8.27 & 36.80 & 45.15 & 17.20 & 49.40 & 61.99 \\
427.8 & 9.03 & 53.46 & 61.18 & 17.85 & 66.13 & 77.80 \\
570.4 & 9.42 & 70.19 & 76.46 & 17.86 & 77.80 & 91.86 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of numerical results for varying amounts of steel reinforcement.  
In addition, when the compressive strength of concrete increased from 21 MPa to 35 MPa, the displacement ductility index of the specimen was improved by 66.8%. Therefore, the compressive strength of concrete effects on improving the ductility of the RC beams than on enhancing the load-bearing capacity of the RC beams.
3. As the recovery stress of the used Fe-SMA strip increased, the initial crack load and initial stiffness increased. However, the increase in the recovery stress of the Fe-SMA strip improved about 0.03% of the ultimate load. Those results concluded that the recovery stress of the Fe-SMA strip improves the initial stiffness and serviceability of the RC beam.
4. As the amount of Fe-SMA strip increased, the initial crack load, yield load, and ultimate load were all increased by more than 80%. However, as the amount of Fe-SMA strip increased, the displacement ductility of the RC beams decreased.
5. As the amount of tensile reinforcement increased, the yield and ultimate load of the RC beam strengthened with the Fe-SMA strip were greatly improved, but its ductility greatly decreased. In addition, it was observed that the smaller the amount of tensile reinforcement, the higher the strengthening efficiency of the Fe-SMA strip.
6. In this FE model, the constitutive models of concrete, steel reinforcement, and Fe-SMA strip were idealized for the simulation, and interfaces between concrete and steel reinforcement and between concrete and Fe-SMA strip were assumed to be perfectly bonded. For future research, to accurately predict the flexural behavior of RC beams strengthened with Fe-SMA, more elaborated constitutive material models and bonding interface model between concrete and steel materials need to be employed.  
The authors declare no conflict of interest.