PSI - Issue 57

Elena Sidorov et al. / Procedia Structural Integrity 57 (2024) 316–326 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

325

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relevant wheel load range load range relevant for light crane service

relevant wheel load range load range relevant for light crane service

(a)

(b)

Fig. 10. Dependency of rail weld pressure on (a) weld size a and (b) weld length h

5. Summary and outlook A concise overview about the local stresses in continuous and intermittent rail welds of crane runway beams due to the wheel load introduction was presented. In a parametric study with Finite Elements, the significant influences on the vertical force per unit length (referred to as ‘ weld pressure ’ in the paper) in chain intermittent rail welds were investigated taking the technical contact between flange and crane rail into account. The major findings can be summarized as follows: 1. The interaction at the interface between rail and flange of the crane runway beam has to be characterised as technical contact. This contact significantly affects the magnitude of the weld pressure, that means the proportion of the wheel load that is carried by the rail welds. A wedge-shaped gap under the rail with a maximum gap size of 50 µm is proposed to simulate the technical contact in a numerical analysis. 2. The simplified formula (Kuhlmann et al., 2022) to calculate the nominal stress in chain intermittent rail welds tends to overestimate the weld pressure calculated by the FE model for increasing rail stiffness. It is advisable to improve this formula to allow for a more efficient design. 3. The simplified formula tends to underestimate the weld pressure calculated by the FE model for increasing stiffness of crane runway beams. An improvement is necessary for safety reasons. Further investigations are planned in near future to study the influence of a wheel load eccentricity in x - and y direction on the weld pressure. Furthermore, the influence of additional global shear stresses will be considered in detail. An extension of the investigations to staggered intermittent rail welds is intended. Finally, it has to be investigated how the simplified formula, that has been recently proposed by Kuhlmann et al. (2022), can be modified to allow for a more efficient fatigue design of all types of rail welds. References DIN 4768 (1990): Determination of surface roughness values of the parameters Ra, Rz, Rmax by means of electrical contact instruments. Former German Standard. DIN 4768-1 Beiblatt 1 (1978): Determination of surface roughness values of parameter Ra, Rz, Rmax by means of electrical stylus instruments; conversion of parameter Ra to Rz and vice versa. Former German Standard. EN 10163-3 (2004): Delivery requirements for surface condition of hot-rolled steel plates, wide flats and sections – Part 3: Sections. EN 1993-1-9 (2005): Eurocode 3 – Design of steel structures. Part 1-9: Fatigue. EN 1993-6 (2007): Eurocode 3 – Design of steel structures. Part 6: Crane supporting structures. EN ISO 4287 (1998): Geometrical Product Specifications (GPS) – Surface texture: Profile method – Terms, definitions and surface texture parameters.