## 4 Numerical Modeling and Methodology
### Case-Study Frames
The columns are responsible for supporting beams that manage the loads from roofs or floors through a configuration of stirrups and longitudinal reinforcement, which correspond to the required cross-sectional load-carrying capacity. Additionally, at each intersection of beams and columns, the models depict a monolithic configuration representative of wet connections. In this structural arrangement, extending rebar is integrated into a cast-in pocket located at the column face. In the FEMs, static vertical loads were applied to replicate typical gravity demands acting on the frames. A constant axial compressive load of 450 kN was applied to the top of each column to represent the self-weight of roof and cladding elements, as well as the tributary floor area. This load magnitude was based on the axial load ratio used in the ACPH-1-300 experimental benchmark and scaled proportionally to the column capacity and tributary area in the case-study frames. The self-weight of all structural elements was automatically included in the model using ABAQUS [33] gravity load definitions. No additional live or dynamic vertical loads were applied during the time-history analysis in order to isolate the seismic response. This loading configuration reflects typical industrial precast buildings, where vertical demands are moderate but axial stability plays a significant role in seismic performance. The characteristic compressive strength of the concrete is designated at a relatively low characteristic value of 20 MPa, while the embedded steel reinforcement within the columns and beams exhibits a yield stress of only 250 MPa, accompanied by minimal strain hardening effects. These comparatively low strength parameters can be attributed to older manufacturing practices and the potential presence of subpar alloy compositions that may not have been subjected to contemporary quality assurance measures. Additionally, the confinement reinforcement within the columns is presumed to be insufficiently provided, leading to a scenario where, upon the buckling of the primary longitudinal bars or the spalling of the concrete cover, there is a significant reduction in the ultimate displacement capacity. Consequently, the structural response post-peak is characterized as brittle, predominantly driven by shear cracks or failure due to unconfined compression in the core of the column. The mechanical characteristics of both the concrete and the reinforcing steel utilized in this design framework are provided below in Tables 1 and 2, respectively. The mechanical characteristics outlined in Tables 1 and 2 pertain to C20 concrete and B250 reinforcing steel, both of which are inferior to the strength and ductility standards generally stipulated in contemporary seismic design regulations. As per TBEC (2018) [17] and Eurocode 2 [41], modern reinforced concrete edifices typically utilize concrete grades of C30/37 or superior, in conjunction with reinforcement grades such as B420C or B500B, which offer enhanced yield strength, strain capacity, and energy dissipation properties. The selection of lower-strength materials in this investigation was deliberate, intended to emulate the attributes of non-compliant precast reinforced concrete frames, particularly those erected in Turkish's prior to the 1998 code amendments. This classification of structures--common in low-rise industrial contexts--often demonstrates insufficient confinement, substandard detailing, and low-strength concrete, all of which aggravate seismic susceptibility [5]. From a performance perspective, the employment of C20 concrete and B250 steel results in restricted ductility, premature initiation of stiffness reduction, and heightened vulnerability to brittle failure, particularly under cyclic loads. These circumstances place considerable demands on the connection region, thereby underscoring the significance of auxiliary energy-dissipating systems such as the ACPH.