PSI - Issue 81

Mykola Pidgurskyi et al. / Procedia Structural Integrity 81 (2026) 539–546

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Fig. 3. Boundary conditions of the steel perforated beam; a) horizontal; b) double-pitched; c) arched beam.

To reduce the concentration of transverse stresses in the support zones, additional stiffening ribs 20 mm thick were modeled at both beam ends, protruding 20 mm beyond the beam outline (Fig. 4). These stiffeners were assumed to be rigidly welded to the structure and serve to redistribute local forces without introducing significant additional bending moments due to their small eccentricity. The thickness and projection of the stiffeners were aligned with the finite element size (20 mm), ensuring mesh stability and result accuracy. The central joint of the beam was modeled as a welded butt joint without additional plates. To ensure objective comparison of the weight characteristics of the analyzed beams, the mass of the supporting elements (stiffeners, plates) was not included in the calculations. The applied loads accounted for the weight of the roof, snow load, and the self-weight of the beam. The consideration of the self-weight of the beam is essential, since an increase in the slope leads to both a longer beam length and greater total weight. The analyzed roof system corresponds to an industrial building with a span of 24 m and a beam spacing of 4 m. The roof dead load was taken as 0.25 kPa, and the snow load as 1.4 kPa. Thus, the design roof load is 1.65 kPa, resulting in a distributed load on the beam of q = 6.6 kN/m.

Fig. 4. Geometric parameters of the horizontal perforated beam.

Preliminary analytical calculations showed that for a 24 m span under the given loads, an IPE 500 section is required according to the first limit state. Since the perforated beam is higher than the original solid one, for optimal use of the cross section, an IPE 400 profile was selected as the base beam, from which the perforated variant was derived. The perforated beam was formed by cutting and sequentially welding an original IPE 400 section, with perforation opening diameter d = 518 mm, spacing s = 570 mm, and total beam height h = 657.6 mm (see Fig. 4). The parameters of the analyzed beams comply with design standards (EN 1993-1-13:2024, Eurocode 3, 2024; Fares et al., 2016). Horizontal beams were analyzed without pitch, while the double-pitched beam had a 5° slope. The arched beam had a circular profile with a rise at midspan equal to that of the double-pitched beam – 2.1 m. Additional ribs and plates were modeled in the eaves and apex zones for beams with haunches. The haunch length in the eaves joint was 2880 mm, in the apex joint – 2260 mm, with an additional height of 395 mm. The thickness of the vertical haunch plate corresponded to the web thickness of the I-beam (8.6 mm), and the horizontal plate thickness and width corresponded to the flange dimensions – 13.5 mm and 180 mm, respectively. The haunches were modeled for all three beam types: horizontal, double-pitched, and arched (Fig. 5).