Issue 61

M. Khalaf et alii, Frattura ed Integrità Strutturale, 61 (2022) 308-326; DOI: 10.3221/IGF-ESIS.61.21

Figure 29: Effective Width of Exterior Beams with (T-section).

It can be deduced that existence of openings in slab more away from exterior beams (y o =0.36) resulted in reduction in the effective width at sec.'s 1,2 and 3 by only 1.5% , 9.3% and 20% with respect to that without opening while by locating them more closing to it (y o =0.64) decrease the effective width by 26.5% ,43.1% and 45.7% respectively. It is also observed that the effective width at section sec.1 has approximately the same vales for M1 and M3. On the other hand, existence of openings in slab more away from interior beams (y o =0.64) resulted in reduction in the effective width at sec.'s 1,2 and 3 by only 3.3%, 0% and 14.5% with respect to that without opening while by locating them more closing to it (y o =0.36) decrease the effective width by 25.4%, 50.8% and 52.3% respectively. It is obvious that the effective width at section sec.2 has exactly the same vales for M1 and M2. Finally, locating the openings more away from supporting steel beams as possible as could makes their existence undesired effects on estimated effective width decreased as structurally preferred.

(b)

(a)

Figure 30: Influence of loading increments vs. effective width for exterior beams. (a) Sec.2; (b) Sec.3.

Concentrated loads Unfortunately, recorded results of estimated effective width at sec.1 are suppressed from analysis as a result of its location duo to their interruptions where high stress concentrations existed; as initially expected; at regions in vicinity to concentrated loads points of applications. Fig. 30 represents the normalized effective width (  ) at sec.'s 2 and 3 for exterior supporting steel beams due to different loading levels till failure. Except some interrupted results at start, there is no noticeable difference in effective width estimated at mid-span (sec.3) for models M1 and M3 which may be interpreted by locating openings more away enough from beams axes. In the other hand, the effective width at Sec. 2 in model (M3) decreased by about 20% in average compared to that for model (M1) which may be due to its closer location to stress concentration region near openings corners. For model (M2) where openings are located closer to exterior beams axes, the effective width estimated at both

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