## 5 Verification and Validation
### Structural Performance of Numerical Model  
The methodology of modeling the plate-reinforced large CFT connection described previously was verified and validated in terms of its structural performance. The experimental data in [16] were used for validating the numerical model. [PERSON] performed cyclic tests based on AISC [32] to assess the rotational performance of a ribbed through-diaphragm connection with an HSS column with dimensions of \(300\times 12\) mm and a H-beam with dimensions of \(400\times 200\times 8\times 13\) mm, which was numerically modeled, as shown in Figure 7. The connection modeled in LS-DYNA is shown in  
Figure 6: Verification of blast loadings based on UFC 3-340-02. (**a**) \(P_{s}\); (**b**) \(I_{s}\); (**c**) \(P_{r}\); (**d**) \(I_{r}\). Figure 7a. A monotonic loading with the maximum drift angle of 0.05 radians was assigned around the beam free end of the numerical model to investigate the rotational capacity of the connection. For verification, the LS-DYNA results were compared to those analyzed using an alternate finite element code, ABAQUS [22]. The mesh of the LS-DYNA model was imported in ABAQUS, as shown in Figure 7b. The contact and tie algorithms, material properties, loading and boundary conditions, element formulation of eight-node linear brick element with reduced integration, and hourglass control were defined similarly. Results are presented in Figure 8, and show that the LS-DYNA model well predicted the experimental moment-drift relationship in terms of the stiffness in the elastic range and the yield and maximum strengths. Furthermore, it is seen that there were negligible differences in the moment-drift relationship between the two different codes. Figure 9 enables comparison of failure modes of beam web and flange for the test specimen and maximum principal strain distributions on beam web and flange for numerical models in ABAQUS and LS-DYNA. This figure shows that the maximum principal strains were concentrated at the failure locations of beam web and flange for the test specimen. The modeling methodology was therefore considered to be verified and validated. Figure 8: Moment-drift curves calculated numerically using finite element codes and obtained experimentally by [PERSON] [16] for verification and validation. Figure 7: Finite element models for verification and validation. (a) LS-DYNA model; (b) ABAQUS model. Further study was performed using finite element models, as shown in Figure 10, (1) to show the rotational performance of the proposed plate-reinforced large CFT connection, which has a \(1000\times 1000\times 40\) CFT column and the \(700\times 300\times 13\times 24\) H-beam, and (2) to ensure the accuracy of the simulation results. The connection, shown in Figure 2, was modeled in both LS-DYNA and ABAQUS, as shown in Figure 10a and 10b, respectively. The results were generated using the moment-drift curve normalized by the plastic moment of beam, \(M_{p}\), as shown in Figure 11. As expected, the two codes led to similar rotational responses. Further, the connection models attained the plastic moment, \(M_{p}\), at drift angles of approximately 1.5% to 1.7% radians and approximately 1.4 \(M_{p}\) at the drift angle of 4% radians. This indicates that the proposed plate-reinforced large CFT connection showed satisfactory rotational performance based on AISC [32]. It is therefore considered that the structural performance of the proposed connection was numerically verified. Figure 10: Finite element models of plate-reinforced large CFT connection. (**a**) LS-DYNA model; (**b**) ABAQUS model. Figure 9: Comparison between failure modes of test specimen [16], with permission, and maximum principal strain distributions of numerical models at the drift angle of 5.0%.