PSI - Issue 59

Volodymyr Romanіuk et al. / Procedia Structural Integrity 59 (2024) 471 – 478 Volodymyr Romanіuk et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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From the point of view of the construction of a continuous perforated beam, it is considered as a set of structural elements (walls and shelves) that are connected to each other at nodal points. If the relations between forces and displacements are known for each element, it becomes feasible to describe the properties and investigate the behavior of the structure as a whole. The beam was discretized using a mesh of finite elements based on the conditions a ≥ 2 t and b ≥ 2 t , where a and b represent the length and width of the finite elements; t is the thickness of the elements (shelve, wall) under consideration. The finite elements of the shelf and the wall are square, while those near the hexagonal holes are formed by three- and four-node plates. The inclined facet of the hole is set at an angle α = 45°. These specified dimensions and shapes of the finite elements ensure a high level of accuracy in the calculations. The fixation of the ends of a perforated two-span beam with equal spans of l = 6 m is established as follows: the leftmost support is hinged fixed, the rightmost support is hinged movable, and the intermediate support is hinged movable. To fasten the beam from the plane of action of the load, transverse elements are used along the upper belts of the profile with a spacing of 1 m (see Fig. 1). This arrangement effectively eliminates transverse deformations in the modeled structure, closely approximating its behavior to that of the real structure. The following options for the design of the intermediate support part of a continuous perforated beam are considered: 1) type 1: without transverse stiffeners along the axis of the intermediate support and with unwelded holes to the left and right of the support (Fig. 2); 2) type 2: with transverse stiffeners along the axis of the intermediate support and with unwelded holes to the left and right of the support (Fig. 3); 3) type 3: without transverse stiffeners along the axis of the intermediate support and with welded holes to the left and right of the support (Fig. 4); 4) type 4: with transverse stiffeners placed along the axis of the intermediate support and with welded holes to the left and right of the support (Fig. 5). The objective of this study is to investigate the stress-strain state of various types of intermediate supports in uncut perforated beams with an I-beam cross-section. These beams were obtained from the original profiles No 20, 30, 40, 50, 60 (DSTU 8768:2018), manufactured from the S235 steel. The investigation aims to discern patterns and determine the optimal application areas for each type of support. All beams, regardless of the height of the original profile, share a common cross-section height development coefficient k = 1.5. the height of the perforation hole is set to be half of the original profile's height. In the process of beam modeling, real dimensions incorporating all structural features of the supporting parts were considered. The composition of the intermediate support part of the beam, depending on its height, includes two sections with length l 1 = 700…1800 mm on both the left and right sides of the support axis. Here, l 1 represents the distance from

Fig. 2. Support section without stiffener and with unwelded holes (type 1).

Fig. 3. Support section with stiffener and with unwelded holes (type 2).