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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Fig. 4. Deformation of load introduction region: a) unrestrained flange bending, b) suppressed flange bending. Explanation: 1 – rail, 2 – rail weld, 3 – top flange of runway beam, 4 – web of runway beam, 5 – transverse stiffener

3.2. Test specimens In order to investigate the pressure p in the rail welds of a rail that is fastened to a top flange, supported only by a web, crane runway beams with a length of 3,50 m and a hot-rolled cross-section (HEA 280) of steel grade S355J2 with a flat rail (50 × 30 mm and 50 × 50 mm respectively) of steel grade S355J2 were produced by three different steel construction companies. These beams were cut into pieces to obtain the small-scale test specimens shown in Figure 5a and Figure 5b. Six specimens were taken from crane runway beams with chain intermittent rail welds as shown in Figure 5a and four specimens from beams with staggered intermittent rail welds as shown in Figure 5b. In order to simulate the suppressed flange bending, three additional test specimens were produced. For this purpose, a flat rail (50 × 30 mm) of steel grade S235 and a length of approx. 2 m was attached to a plate (15 × 100 mm) of steel grade S235 and a length of approx. 2 m by chain intermittent fillet welds. Subsequently, this member was cut into pieces as shown in Figure 5c. The measured dimensions of all specimens are summarized by Table 1.

Fig. 5. Geometry of the test specimens – specimens with top flange being exclusively supported by the web: a) chain intermittent rail welds (Type 1), b) staggered intermittent rail welds (Type 2); c) test specimens with uniformly supported top flange (Type 3); d) weld detail

3.3. Test set-up The vertical strains of the specimens were measured in elastic compression tests that were performed at the testing laboratory ‘Forschungs- und Materialprüfanstalt (FMPA)’ of Brandenburg University of Technology. All test specimens were loaded on the top of the rail through a thick load distributing steel plate that were connected with an actuator by means of a spherical loading head to minimize undesired eccentricities. As described in 3.2, the supporting length b sup of the 13 test specimens varied. During the test, each test specimen was loaded up to F = 100 kN with a velocity of 2 kN/s. After a pause of 10 seconds, the load was reduced with the same velocity. Each specimen was at least tested twice.