Abstract
Thin-walled plate girders occupy a special place in structures and construction due to their efficiency in carrying loads. The permanent deformations of the girder lead to a lack of stability, which necessarily leads to its replacement. Replacing permanently deformed thin-walled load-bearing structures requires large financial outlays. Technological prestressing is one of the most effective methods for studying and treating permanent deflections in girder elements. This study looks at the defection of welded thin-plate S235JR steel girders, examining how technological tensioning effects interact with different loading conditions. Four configurations were investigated: welded in bottom caps, welded in two side caps (two configurations), and welded in two side caps and bottom caps. Five loads of P (20, 40, 60, 80, and 95) kN were applied to the seven sensor positions of each girder section (A, B, C, and D). All points were examined during the 95 minutes of cooling time. For technological compression, the results showed that there is a convergence between the analytical solution and the experimental results, as the most significant deviation achieved in the analysis was 5.21 mm compared to 6 mm experimentally. When the grinder is loaded with the force P = 50N, the maximum defect achieved at grinder A4 is 4 mm, compared with 1mm at grinder A2. In prestressed grinder B, the deflections that were reached were 2.50 mm, 3.50 mm, and 3.52 mm in the analytical, experimental, and FE numerical models, respectively. The tensions that were reached were 36.96 MPa, 44.28 MPa, and 27.93 MPa.