## 6 Performance Levels of a Code-Designed Structure  
In this section, the same procedure used to obtain the results shown in Figures 15-18 is applied to a structure designed by an experienced practicing engineer ([PERSON] et al., 1993 [36]; [PERSON] et al., 1993 [37]) as per the seismic provisions of the Uniform Building Code (UBC, 1988 [38]). This structure could be considered more representative of existing structures and be closer in design terms to buildings located in seismic-prone regions, in comparison to the structures considered in the previous sections. It is the eight-story moment-resisting steel frame showed in Figure 19, where the W-Shapes of A-36 steel for beams and columns can be observed, together with the dimensions and the points with the largest rotations (red dots); depicted green symbols indicate change in the columns section (at midstory). This structure just meets the UBC (1988) [38] requirements for earthquake design ([PERSON] et al., 1993 [36]; [PERSON] et al., 1993 [37]). The considered gravity load (including dead load and live load) in the non-linear analyses is 52.54 kN/m at interstory levels and 43.78 kN/m at roof level. The self-weight of the elements is considered in the analyses. Figure 19: Realistic code-designed moment-resisting steel frame to assess seismic performance levels. Red dots denote selected plastic hinges. Green symbols indicate the section change at midstory. Figure 18: Examples of acceptance criteria for the 10-story building. Part 2. These uniformly distributed loads are based on the loads per area unit reported for this structure ([PERSON] et al., 1993 [36]; [PERSON] et al., 1993 [37]) and the consideration that the frame corresponds to a central frame and that the tributary areas for each side of the beams are half of the area for a given floor. For the eight-story building, the first horizontal vibration period is T1h = 2.048 s, the second is T2h = 0.738 s and the third one is T3h = 0.415 s. The same corresponding periods, but for the vertical response are T1v = 0.230 s, T2v = 0.151 s and T3v = 0.126 s, respectively. [PERSON] et al., 1993 [36] reported only the fundamental period for the horizontal component. Some assumptions were made with the available information found in [36], as mentioned above. This led to some variation in the fundamental period since a period of 2.4 s is indicated in [36]. The structure in Figure 19 is to be subjected to the records in Table 1 for the non-linear dynamic analyses too, plus other four Mexican records listed in Table 10. The corresponding response spectra are depicted in Figure 20 for the additional records. The non-linear response is computed as before, i.e., the OpenSEES program [32], the pre- and post-processor GiD [33] and the coupling interface GiD+OpenSees Platform [34] are used with the same previously stated assumptions and nomenclature, except that the steel frame in Figure 19 and its characteristics are considered. Distributed plasticity with fibers in all the elements is assumed. However, in this case, the P-delta effect is not added for simplicity and at intersections the joint offset node was not taken into account. The results are shown in Figures 21-23 for the red dots in Figure 19. The W18 \(\times\) 40 beams on the 7 th floor have a yielding flexure moment My = 278.1 kN-m and a yielding rotation \(\theta\)y = 0.0076 rad. It is observed that the beam undergoes into the inelastic range for almost the 11 ground motions (except for the PETA-7S-LS case) and that, when both