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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point 11 experiences the most stress for support types 1 and 3, where stiffeners are absent, which is also expected. In Fig. 8, the distribution of tangential stresses at the calculation points of cross sections 1-1, 2-2 and 3-3 is illustrated. They are unevenly distributed in cross sections 1-1 and 2-2 for support types 1 and 2 since the wall of such beams is weakened by a perforation hole and consists of two identical parts separated by a hole. Moreover, the graphs of changes in stress values for these two types of supports completely coincide regardless of the presence or absence of a supporting stiffener. In the same cross sections for supports of types 3 and 4, the tangential stresses are distributed more evenly without a sharp change in their values since the entire wall along the height of the beam is continuous. In cross section 3-3, the stress distribution graphs for types 2 and 4 almost coincide due to the presence of stiffeners. Notably, in the absence of support stiffeners (types 1 and 3), lower stresses are observed at the calculated support points with welded holes. Thus, the presence of welded holes and supporting stiffeners contributes to the improvement of the supporting parts' performance, as stress concentration is largely eliminated, although the stress values in all cases remain considerably below the calculated resistance of steel. The analysis of the distribution graphs of tangential stresses in the calculated cross-sections is fully applicable to the distribution graphs of normal stresses (Fig. 9). Furthermore, it is noteworthy to mention that the existing Ukrainian and European standards for the design of steel structures consider the boundary conditions of bolted and welded joints in an idealized manner – as rigid, Cross section 1-1 Cross section 2-2 Cross section 3-3

Fig. 8. Graphs of the distribution of tangential stresses at the calculated points of the cross sections 1-1, 2- 2 і 3 -3.

Cross section 1-1

Cross section 2-2

Cross section 3-3

Fig. 9. Graphs of the distribution of normal stresses at the calculated points of the cross sections 1-1, 2- 2 і 3 -3.