## 4 Numerical Modeling and Methodology
### Validation of the FEM  
The methodologies outlined herein were subsequently applied to refine the outcomes of the FEM model based on the experimental work by [PERSON] et al. [15]. This research's finite element model was fine-tuned utilizing the outcomes from a half-scale precast beam-column subassembly assessment (specimen ACPH-1-300) as documented by [PERSON] et al. [15]. The experimental setup featured a single-bay frame segment, in which the ACPH device was located 300 mm from the face of the column. The specimen incorporated C35 concrete and a combination of Q235 and Q345 steel plates to emulate the fusing and confinement components of the ACPH framework. A continuous axial force of 450 kN was applied to the column, while the beam underwent reversed cyclic lateral loading through a horizontal actuator. Throughout the testing process, deformation was observed in the 3 mm Q235 fuse plates, accompanied by minor flexural cracking at the extremity of the beam. No significant damage was detected in the column or the surrounding concrete. The specimen achieved a ductility ratio of 9.39, while the associated viscous damping ratio stabilized at 10%, indicating a consistent hysteretic response with well-regulated plasticity. These reference values were employed to authenticate the FEM by analyzing force-displacement loops, patterns of damage localization, and the capacity for energy dissipation. In Figure 6, a comparison is illustrated between the hysteretic curves produced under the cyclic load described in the original paper and those derived from the FEM model. The analysis of this figure suggests a strong correlation between the FEM results and the reference frame established in the study. Initially, the overall configurations of the loops exhibit a strong similarity, particularly in relation to the cyclic \"pinching\" phenomenon observed near the origin and the peak force levels achieved at substantial displacements. This observed congruence suggests that the model effectively reflects both the degradation of stiffness and the incremental inelastic response, thereby bolstering the reliability of the calibrated material parameters and boundary conditions. Furthermore, the maxima in strength and the unloading gradients in the simulated loops are in close alignment with experimental data over multiple cycles, indicating that the selected constitutive models, such as CDP for concrete and elastoplastic laws for steel, accurately replicate the stiffness and ductility features of the specimen. Although minor deviations are noted in the higher-amplitude cycles, the proximity of the loops is sufficient to infer that the FEM effectively reproduces both the overarching hysteretic response and a significant portion of the localized energy-dissipation behavior observed in experimental settings. In addition to aligning with the global hysteretic response, the computational model was assessed for its proficiency in mirroring the damage localization phenomena observed during the experimental evaluation. In the ACPH-1-300 specimen, yielding was distinctly focused within the 3 mm Q235 steel fuse plates, while the adjacent concrete, encompassing the beam-column interface and column face, remained predominantly intact, apart from minor superficial cracks. The plates demonstrated stable inelastic buckling under compressive forces and elongation under tensile forces, with no signs of fracture or instability detected. The FEM effectively captured this behavior through the plastic strain distribution and von Mises stress profiles, indicating that inelastic deformation was sharply restricted to the specified fuse regions. The surrounding concrete and longitudinal reinforcing elements predominantly retained their elastic characteristics, aligning with the experimental data. Furthermore, the FEM accurately forecasted the lack of tensile or compressive damage in the concrete, aside from trivial surface phenomena.