## 4 Results and Discussion
### Discussion  
The value of \(\beta\) should not exceed 1.3, according to the AISC [44]. The value of \(\beta\) was determined as 1.16 from Equations (6)-(8). If this value was lower than 1.3, it indicated that the value of the friction coefficient between the CP and CM was reasonable. The maximum tensile and compression strains of the CP were measured as 1.75% and 2.69%, respectively. Although the BRB resisted up to 2.69% axial compression demands, local and global deformation did not occur on it.  
The numerical results demonstrated that the kinematic and isotropic hardening parameters had a significant effect on the hysteretic behavior of BRB. When the value of the friction coefficient was increased, it led to compression over-strength and less ductility for the BRBs. While the friction coefficient between the contact surfaces of the steel plates of slip-critical connections in the steel frame had major effects on the numerical results, the calibrated material models had minor effects on it as the steel frame with slip-critical connections was within the elastic limit during the test.  
The pretension load had a major effect on the tensile and compression strength of BRBF. While the pretension load of 35 kN predicted the cyclic response of BRBF under the tension demands well, the pretension load of 75 KN predicted its cyclic response under the compression demands well. Both calibrated material models had almost similar hysteretic predictions for the FEM of BRBF. However, the calibrated Tremblay and Korzekwa [46] material model was better matched with the test results than the calibrated [PERSON] et al. [36] material model.  
[PERSON] and [PERSON] [64] performed FE analysis using the isotropic hardening steel material model for CP on the BRBs. However, even if this material model performs an acceptable prediction for the cyclic behavior of steel material, it does not have a better predictive ability than the combined isotropic-kinematic hardening steel material model. The finite element analyses in this paper and the literature [35; 36; 38; 46; 65; 66] confirmed this phenomenon. Many studies [36; 51; 52] demonstrated that the finite element analysis adopting the C3D8I element can more accurately predict the experimental results because it can overcome the shear locking effect. Moreover, the actual normal and tangential behaviors of contact pairs in both BRB and slip-critical connection were properly predicted by hard contact and penalty friction, respectively [47; 48; 49; 50]. For these reasons, the numerical results that predicted experimental behaviors well in this paper and the past studies demonstrated the accuracy of the material and contact models used in all FEMs.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Demands** & \multicolumn{3}{c}{**Calibrated [PERSON] and [PERSON] [46]**} & \multicolumn{3}{c}{**Calibrated [PERSON] et al. [36]**} & \\ \hline \multirow{8}{*}{Tension} & \multirow{3}{*}{IDR} & \multicolumn{2}{c}{Max. Lateral} & \multirow{3}{*}{Error} & \multirow{3}{*}{R\({}^{2}\)} & \multirow{3}{*}{Drift Ratio} & \multicolumn{2}{c}{Max. Lateral} & \multirow{3}{*}{Error} & \multirow{3}{*}{R\({}^{2}\)} \\  & & & Force (KN) & & & & & & & \\  & & Exp. & Num. & & & & & Exp. & Num. & \\ \cline{1-1}  & 1.00\% & 471 & 529 & 12.31\% & & 1.00\% & 471 & 54