# Seismic Comparison of Hybrid Steel-Reinforced Concrete and Conventional Frames
## 3 Results and Discussion
### Two-Story Buildings  
For the two-story r/c buildings, the IDR-X has greater values at the first-story level than the other levels (Figure 6a), up to 1.95%, within the LS limit [59]. In the second-story steel buildings (Figure 6b), the IDR-X increases more at the second story than the other stories, with a maximum value of 2.95%, which is within the CP level [59]. The IDR-X of the hybrid building with a \"fixed-pinned\" interconnection (Figure 6c) has a maximum value of 2% at the first story and 4.1% at the second story within the CP level [59]. For the steel frame, the IDR-plotline for the earthquake of Kobe with 90\({}^{\circ}\) is omitted because it exceeds the limits of [59], showing structural failure, while this effect does not appear in the r/c and hybrid frames.  
The IDR-Y of the r/c model is analogous to the IDR-X, displaying the highest number of 2.6% for the first story (Figure 7a). The IDR-Y has an upper limit of 3.9% for the reinforced concrete and 3% for the hybrid buildings (Figure 7b,c). The IDR tends to have greater values at the Y-axis than the X-axis for the considered buildings (Figures 6 and 7). The maximum IDR-X for the two-story hybrid buildings is greater by 39% than the respective one for r/c (Figures 6 and 7). The IDR-Y for the hybrid building has the most outstanding value, smaller by 26% for the steel building and greater by 15% for the r/c one (Figures 6 and 7).  
The PFA/PGA-X rises with the height of the considered buildings by up to 2.45 for the r/c frame, 3.7 for the steel one, and 2.45 for the hybrid one, as in Figure 8. The PFA/PGA-Y has the most significant values at the building's top (Figure 9), up to 3.5 for the reinforced concrete building, 4.2 for the steel, and 3.7 for the hybrid one. Observing Figures 8 and 9, the PFA/PGA tends to have similar values for the hybrid and r/c buildings while presenting a bigger value by 50% for the steel ones compared to other cases on the \(X\)-axis and correspondingly by 13\(\sim\)20% on the \(Y\)-axis.  
The base shear ratio \"FX ratio\" presents 4.5 as the top value for the two-story steel building and a minimum of 1.69 for the r/c ones (Figure 10). The FX ratio has very close values for the two interconnection types of hybrid structures, shown in Figure 10 as 1.86 for the steel part's \"fixed\" support on the r/c one and 1.92 for the \"fixed-pinned\" support.  
Figure 6: IDR comparison along the \(X\)-axis for (**a**) r/c, (**b**) steel, and (**c**) hybrid (fixed-pinned connection) two-story buildings.  
Figure 7: IDR comparison along the \(Y\)-axis for (**a**) r/c, (**b**) steel, and (**c**) hybrid (fixed-pinned connection) two-story buildings.  
As observed in Figure 11, the base shear ratio \"FY ratio\" presents the most significant value of 3.5 for the steel building and the smallest one of 2.3 for the r/c one, with intermediate values for the hybrid buildings as 2.4 for the \"fixed\" and 2.3 for the \"fixed-pinned\"  
Figure 8: “PFA/PGA” comparison on the \(X\)-axis for (**a**) r/c, (**b**) steel, and (**c**) hybrid (fixed connection) two-story buildings.  
Figure 10: Base shear ratio “FX ratio” comparison for two-story buildings.  
Figure 9: “PFA/PGA” comparison on the \(Y\)-axis for (**a**) r/c, (**b**) steel, and (**c**) hybrid (fixed connection) two-story buildings.  
support. The base shear ratio for the hybrid buildings tends to have values close to the ratio for the r/c buildings (Figures 10 and 11).