PSI - Issue 75

Elena Sidorov et al. / Procedia Structural Integrity 75 (2025) 276–288 Elena Sidorov et al. / Structural Integrity Procedia (2025)

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those of the unstiffened crane runway beam. The increased stiffness of the top flange results in a higher stressing of the rail weld region. In Figure 11c, the weld pressures p are compared, which are obtained from the FE beam model with and without transverse stiffener and that are calculated by Equation (2). The weld pressure p according to Equation (2) gives an acceptable estimate for the beam model without stiffener, that tends to be more conservative for greater wheel loads. The weld pressure p of the beam model with transverse stiffener is underestimated by Eq. (2) for any wheel load level.

Fig. 11. FE model of Sidorov & Euler (2024) with highlighted (blue) modifications: a) modified structural system with dimensions in mm, b) modified boundary conditions at the load introduction section; c) weld pressure of the beam models with and without transverse stiffener 7. Summary and outlook The nominal stress of intermittent rail welds of different arrangements has been studied in elastic loading tests on small scale specimens taking into account the technical contact between the rail and the top flange. The experimental measurements and the accompanying numerical calculations of the vertical strains in the top flange underneath the rail for a representative crane runway beam geometry lead to following findings: 1. The nominal stress of the rail welds seems to be independent on the type of intermittent rail welds. Equations (1) and (2) appear to be applicable to the nominal stress calculation of chain intermittent rail welds of both, the investigated small-scale specimens and full-scale girders. The statement also applies to the nominal stresses of the small-scale specimens with staggered interrupted rail welds. 2. The nominal stress of the rail welds significantly increases in regions where the top flange is transversely stiffened. The Eq. (1) and (2) appear to be unable to capture this stress raising effect on the nominal stress. 3. For crane runway design, it is recommended that rail welds should not be placed directly over transverse stiffeners. 4. Regardless of the type of intermittent rail welds (chain and staggered), a wedge-shaped gap under the rail with a gap size of 50 µm is able to simulate the technical contact in a FE calculation. The technical contact is caused by unavoidable imperfections of the contacting surfaces. The FE model and the results of the parametric study in (Sidorov & Euler, 2024) can be considered as validated by the results of this paper. Further investigations are planned in the near future to investigate the influence of wheel load on staggered interrupted rail welds. The influence of additional global shear stresses will also be investigated in more detail. It is recommended