# Seismic Comparison of Hybrid Steel-Reinforced Concrete and Conventional Frames
## 2 Considered Buildings and Seismic Analysis
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Building Stories**} & \multirow{2}{*}{**Mode Number**} & \multicolumn{3}{c}{**R/C Buildings**} & \multicolumn{3}{c}{**Steel Buildings**} & \multicolumn{2}{c}{**Hybrid Buildings: Fixed Case**} & \multicolumn{2}{c}{**Hybrid Buildings: Fixed-Pinned Case**} \\  & & \multicolumn{1}{c}{**Period (S)**} & \multicolumn{1}{c}{**Participating Mass**} & \multicolumn{1}{c}{**Period (S)**} & \multicolumn{1}{c}{**Participating Mass**} & \multicolumn{1}{c}{**Period (S)**} & \multicolumn{1}{c}{**Participating Mass**} & \multicolumn{1}{c}{**Period (S)**} & \multicolumn{1}{c}{**Participating Mass**} \\  & & \multicolumn{1}{c}{**Period (S)**} & \multicolumn{1}{c}{**Percentage**} & \multicolumn{1}{c}{**Percentage**} & \multicolumn{1}{c}{**Percentage**} & \multicolumn{1}{c}{**Percentage**} & \multicolumn{1}{c}{**Percentage**} & \multicolumn{1}{c}{**Percentage**} \\ \hline \multirow{3}{*}{Two stories} & 1 & 0.414 & 93\% & 0.525 & 96\% & 0.399 & 91\% & 0.429 & 83\% \\  & 2 & 0.414 & 93\% & 0.412 & 96\% & 0.399 & 91\% & 0.429 & 83\% \\  & 3 & 0.375 & 93\% & 0.407 & 91\% & 0.356 & 92\% & 0.394 & 80\% \\ \hline \multirow{3}{*}{Three stories} & 1 & 0.469 & 89\% & 0.616 & 96\% & 0.506 & 89\% & 0.522 & 85\% \\  & 2 & 0.469 & 89\% & 0.446 & 96\% & 0.451 & 89\% & 0.474 & 85\% \\  & 3 & 0.427 & 89\% & 0.436 & 96\% & 0.425 & 90\% & 0.451 & 82\% \\ \hline \multirow{3}{*}{Four stories} & 1 & 0.546 & 87\% & 0.711 & 95\% & 0.559 & 86\% & 0.571 & 83\% \\  & 2 & 0.546 & 87\% & 0.488 & 95\% & 0.559 & 86\% & 0.571 & 83\% \\  & 3 & 0.494 & 87\% & 0.463 & 95\% & 0.504 & 86\% & 0.519 & 82\% \\ \hline \multirow{3}{*}{Five stories} & 1 & 0.569 & 85\% & 0.795 & 95\% & 0.581 & 80\% & 0.601 & 76\% \\  & 2 & 0.569 & 85\% & 0.552 & 95\% & 0.581 & 80\% & 0.601 & 76\% \\  & 3 & 0.517 & 85\% & 0.508 & 95\% & 0.522 & 81\% & 0.545 & 75\% \\ \hline \multirow{3}{*}{Six stories} & 1 & 0.650 & 80\% & 0.863 & 95\% & 0.498 & 80\% & 0.509 & 82\% \\  & 2 & 0.650 & 80\% & 0.603 & 95\% & 0.498 & 80\% & 0.509 & 82\% \\  & 3 & 0.589 & 80\% & 0.54 & 95\% & 0.449 & 80\% & 0.465 & 83\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Modal characteristics of hybrid and conventional buildings. In the seismic analysis, the input excitation angle alters the structural reaction within existing studies, e.g., [41; 42; 43; 44; 45; 46]. Concerning the symmetrical building plan, the current selected excitation angles are \(0^{\circ}\) and \(90^{\circ}\) on X and Y, the primary lateral directions (Figure 4). For the needs of nonlinear dynamic analysis, the \"damping ratio\" [53] value is 5% for the steel buildings and 7% for the structural steel ones, following [53]. The current codes do not refer to the determination of the damping ratio's numerical value for the hybrid buildings. In contrast, one value is necessary to avoid wasting the laborious NLTH analysis performance time. The [PERSON] et al. approach [35; 36] is adopted here to calculate a single damping ratio value for each hybrid building, where the resulting values for the hybrid buildings are 0.0457 for the two-story one, 0.0433 for the three-story one, 0.0363 for the four-story one, 0.0231 for the five-story one, and 0.0214 for the six-story one. The analysis model constructed by SAP2000 [52] simulates the performance of r/c elements under elastoplastic conditions during variable loading by employing pointed hinges on the two ends of the structural elements because of seismic excitation. These elastoplastic point hinges incorporate an essential mechanistic simulation, chosen due to the straightforward incorporation into the used analysis software [39] and compliance with the established theoretical principles and verification methods [2; 4; 5; 6; 7; 8; 9; 10; 52] to maintain this study's interest in the seismic comparison of conventional and hybrid buildings' responses.