Issue 66

A. J. Abdulridha, Frattura ed Integrità Strutturale, 66 (2023) 273-296; DOI: 10.3221/IGF-ESIS.66.17

Figure 24: The story-lateral drift at y-directions of the 12-story buildings with the various types of X-brace sections at the corner and side positions. When the eccentric X-brace is at a corner position, modifying its section is most successful in reducing the brace force for 6-story multi-story structures, as opposed to 9- and 12-story multi-story buildings. Large sections are required for eccentric X-braces to resist earthquake stresses, which drives up the cost of the materials used compared to bracing structures, reducing section size. The study results may show the X-bracing system's ability to strengthen the building's stiffness and minimize displacement. To compensate for eccentricity's effect on rigidity loss, expanding the X-braced member's cross section may help. Moreover, the horizontal movement of eccentric X-braces is more significant. The ductility of the eccentric brace frame varies greatly depending on the X-brace section and eccentricity since an eccentric X-brace can absorb tremendous energy. Height, eccentricity, section size, and the position of the X-brace in steel all influence the frequency with which an architectural design arises in nature. Natural frequency and period of all buildings is shown in Tabs. 10 and 11. A structure's natural frequency is more significant at lower heights and decreases with increasing eccentricity and increases the section size. Because the side position is more flexible, the natural frequency of a structure with an X-brace in the side position is upper than that of a structure with 6-story with an X-brace in the corner and the natural frequency of a structure with an X-brace in the side position is lower than that of a structure with 9 and 12-story with an X-brace in the corner.

Eccentricity (mm)

Building ID

Frequency cyc/sec

Building ID

Frequency cyc/sec

Building ID

Frequency cyc/sec

Building ID SS6-B12-1 SS6-B15-1 SS6-B16-1 SS6-B20-1 SS6-B25-1 SS6-B12-2 SS6-B15-2 SS6-B16-2 SS6-B20-2 SS6-B25-2 SS6-B12-3 SS6-B15-3 SS6-B16-3 SS6-B20-3 SS6-B25-3 SS6-B12-4 SS6-B15-4 SS6-B16-4 SS6-B20-4 SS6-B25-4

Frequency cyc/sec

Building ID SS9-B12-1 SS9-B15-1 SS9-B16-1 SS9-B20-1 SS9-B25-1 SS9-B12-2 SS9-B15-2 SS9-B16-2 SS9-B20-2 SS9-B25-2 SS9-B12-3 SS9-B15-3 SS9-B16-3 SS9-B20-3 SS9-B25-3 SS9-B12-4 SS9-B15-4 SS9-B16-4 SS9-B20-4 SS9-B25-4

Frequency cyc/sec

Building ID

Frequency cyc/sec

SC6-B12-1 SC6-B15-1 SC6-B16-1 SC6-B20-1 SC6-B25-1 SC6-B12-2 SC6-B15-2 SC6-B16-2 SC6-B20-2 SC6-B25-2 SC6-B12-3 SC6-B15-3 SC6-B16-3 SC6-B20-3 SC6-B25-3 SC6-B12-4 SC6-B15-4 SC6-B16-4 SC6-B20-4 SC6-B25-4

0.821 0.862 0.873 0.903 0.931 0.789 0.820 0.829 0.857 0.884 0.639 0.661 0.668 0.690 0.711 0.518 0.536 0.542 0.571 0.576

SC9-B12-1 SC9-B15-1 SC9-B16-1 SC9-B20-1 SC9-B25-1 SC9-B12-2 SC9-B15-2 SC9-B16-2 SC9-B20-2 SC9-B25-2 SC9-B12-3 SC9-B15-3 SC9-B16-3 SC9-B20-3 SC9-B25-3 SC9-B12-4 SC9-B15-4 SC9-B16-4 SC9-B20-4 SC9-B25-4

0.506 0.526 0.531 0.548 0.564 0.490 0.504 0.509 0.521 0.534 0.409 0.421 0.424 0.435 0.446 0.336 0.345 0.349 0.357 0.366

SC12-B12-1 SC12-B15-1 SC12-B16-1 SC12-B20-1 SC12-B25-1 SC12-B12-2 SC12-B15-2 SC12-B16-2 SC12-B20-2 SC12-B25-2 SC12-B12-3 SC12-B15-3 SC12-B16-3 SC12-B20-3 SC12-B25-3 SC12-B12-4 SC12-B15-4 SC12-B16-4 SC12-B20-4 SC12-B25-4

0.349 0.359 0.362 0.371 0.379 0.340 0.348 0.350 0.357 0.363 0.292 0.299 0.301 0.307 0.313 0.244 0.250 0.252 0.257 0.262

0.864 0.894 0.901 0.925 0.946 0.793 0.819 0.826 0.846 0.863 0.648 0.669 0.676 0.694 0.711 0.529 0.545 0.551 0.566 0.581

0.500 0.516 0.521 0.534 0.546 0.484 0.496 0.500 0.509 0.518 0.409 0.419 0.422 0.431 0.439 0.338 0.346 0.349 0.357 0.364

SS12-B12-1 SS12-B15-1 SS12-B16-1 SS12-B20-1 SS12-B25-1 SS12-B12-2 SS12-B15-2 SS12-B16-2 SS12-B20-2 SS12-B25-2 SS12-B12-3 SS12-B15-3 SS12-B16-3 SS12-B20-3 SS12-B25-3 SS12-B12-4 SS12-B15-4 SS12-B16-4 SS12-B20-4 SS12-B25-4

0.346 0.354 0.356 0.363 0.369 0.337 0.343 0.345 0.350 0.354 0.292 0.298 0.300 0.305 0.309 0.245 0.250 0.252 0.257 0.261

0

500

1000

1500

Table 10: Natural frequency of all buildings.

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