## 3 Results
### Parameter Analysis
However, the structural elements of the hooked (135\({}^{\circ}\)) stirrup case exhibited better performance in both base shear and displacement capacity as compared to the straight (90\({}^{\circ}\)) stirrup case. Furthermore, the initial damage zones in the 3D view of the multistoried building, as illustrated in Figures 45-47, showed that the concrete crush began at load factors (LF) of 4.7881, 5.1352, and 4.3378 for straight stirrups (90\({}^{\circ}\)) of Kent-Scott-Park, [PERSON] et al., and Kappos-Konstantinidis, respectively. On the other hand, it demonstrated that the hooked (135\({}^{\circ}\)) case experienced concrete crush starting at load factors of 4.8227, 5.17, and 5.0707 for Kent-Scott-Park, [PERSON] et al., and Kappos-Konstantinidis, respectively. The pushover analyses in the Y-direction are presented in Figure 48 according to the concrete models for the C50 concrete class with the Menegetto-Pinto steel model. Based on these analyses, graphs showing the initial damage status for 90\({}^{\circ}\) (straight) and 135\({}^{\circ}\) (hooked) stirrups are illustrated in Figures 49-51 for the Kent-Scott-Park, Mander et al., and Kappos-Konstantinidis concrete models, respectively. The 3D view of the multistoried building under seismic loading represents concrete crushing, depicted in green. During the pushover analysis of the model building, it was observed that there were differences in the top displacements and base shear peak values between the models for both cases. However, the structural elements of the hooked (135\({}^{\circ}\)) stirrup case exhibited better performance in both base shear and displacement capacity as compared to the straight (90\({}^{\circ}\)) stirrup case. Furthermore, the initial damage zones in the 3D view of the multistoried building, as illustrated in Figures 49-51, showed that the concrete crush began at load factors (LF) of 5.3634, 5.4869, and 5.2569 for straight stirrups (90\({}^{\circ}\)) of Kent-Scott-Park, [PERSON] et al., and Kappos-Konstantinidis, respectively. On the other hand, it demonstrated that the hooked (135\({}^{\circ}\)) case experienced concrete crush starting at load factors of 5.3948, 5.4993, and 5.2843 for Kent-Scott-Park, [PERSON] et al., and Kappos-Konstantinidis, respectively. Within the scope of the study, the results of the 54 analyses, performed using different material models, various stirrup arrangements, and different concrete classes, were evaluated. As a result of these analyses, the initial damage conditions of the structural models were determined. Only concrete crushing was taken into consideration for the initial damage condition, and the load factor values related to concrete crushing are presented in detail in Figure 13:0  
Figure 13:1 [PERSON] et al. in the Y-direction. (**a**) 90\({}^{\circ}\) (C50, LF: 5.4869), (**b**) 135\({}^{\circ}\) (C50, LF: 5.4993). According to the parameter analysis, concrete crush (initial damage) occurs at a significantly lower load factor with a 90-degree stirrup configuration compared to a 135-degree configuration. Concrete crush can be considered as premature failure of an element. It is noted that the tendency of premature failure decreases as concrete grade increases in every case. This can be interpreted as the confining effect of the stirrups decreases as the concrete class increases. Table 3 demonstrates the differences between these two configurations as percentages. The effect of stirrup configuration on load factor levels is decreasing as concrete quality increases, as shown in Figure 13:2 The Kappos-Konstantinidis concrete model is clearly more sensitive to the stirrup configuration in both the X- and Y-directions than other concrete models. It can be observed that the 135-degree stirrup configuration shows better performance than the 90-degree stirrup configuration in all cases except one case. The concrete grade C16 and concrete model [PERSON] et al. combination shows that the 90-degree stirrups configuration is better than the 135-degree configuration.