## 4 Results and Discussion  
### Verification of the FE Model  
To evaluate the ability of the developed FE simulation to estimate the lateral response of beam-column joints using CFRP bars as a longitudinal reinforcement in the beam, a comparison was made between the predicted and experimental CFRP-RC beam-column joint specimens. The next section provides specific comparative results. Figure 11 shows a comparison between the applied load versus SD curves predicted using the FE analysis (noted as \"FEA\") and the experimental one (noted as \"Test\"). In both investigated joints the model predicts the maximum load at a satisfactory level as well as the post cracking behavior.  
Figure 12 presents a comparison between the predicted area of damage occurrence and the experimental results. Clearly, the model was capable of accurately predicting the failure of the specimens. For the specimen JBL10 a large crack opened in the beam area close to the joint connection, while no cracking occurred in the joint body. The corresponding mode of failure predicted by the FE analysis also illustrates damage close to this area, while in the joint core no damage is represented as in the experimental specimen. Only low strain concentration around the CFRP bars is illustrated, which is attributed to the slippage of the CFRP bars.  
Figure 10: Traction versus separation model adopted in the performed FE analysis.  
Figure 11: Comparative lateral load versus SD diagrams of the corresponding specimens: (**a**) JBL5.5—Test, JBL5.5—FEA, JBL5.5—FEA and (**b**) JBL10—Test, JBL10—FEA, JBL10—FEA.  
Figure 12: Verification of FE model prediction of damage area: (**a**) JBL5.5—Test, JBL5.5—FEA, JBL5.5—FEA and (**b**) JBL10—Test, JBL10—FEA, JBL10—FEA.  
Figure 13 illustrates that the developed model can also successfully capture the CFRP bar slippage. In particular, for the specimen JBL10, the predicted slip is almost identical to the corresponding slip calculated in the experimental test. In the case of the JBL5.5 specimen, the FE analysis predicted a smaller slip than that experimentally measured but this still remains within acceptable limits. The observed differences between the experimental results and FE model predictions of slip of JBL5.5 could be attributed to the protentional discrepancies and uncertainties of the CFRP bar and concrete bond slip simulation adopted in the cohesive approach described in Section 3.3.  
Figure 14 represents the energy dissipation calculated from the experimental results simply summing up the amount of energy that was lost over the course of several load-displacement cycles and the energy dissipation extracted from the FE analysis. In terms of energy dissipation, the FE simulation is satisfyingly close to the experimental results.  
Figure 14: Energy dissipation versus SD diagrams, comparison and verification of results: **(a)** JBL5.5—FEA, JBL5.5—FEA and **(b)** JBL10—Test, JBL10—FEA, JBL10s—FEA.  
Figure 13: Verification of slip prediction of FE model in terms of slippage versus SD diagrams of the corresponding specimens: **(a)** JBL5.5—Test, JBL5.5—FEA and **(b)** JBL10—Test, JBL10—FEA.  
According to the validation results, the developed FE simulation can accurately estimate the lateral response of CFRC beam-column joints.