PSI - Issue 81

Roman Samchuk et al. / Procedia Structural Integrity 81 (2026) 184–191

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2. Methodology

2.1. Case study description

2.1.1. Overhead crane A workshop overhead travelling crane is considered. The crane group is assessed as A4, corresponding to a total number of cycles class up to 250,000 cycles within the adopted fatigue framework used for this study. Key characteristics are summarized in Table 1.

Table 1. Overhead crane characteristics used in the case study. Parameter

Value

Rated hoist load

12.5 t

Trolley + lifting system mass

3.5 t

Crane span

12.5m

Wheel arrangement

2 wheels per side (4 total)

Wheel spacing (one side)

3.1m

Crane and trolley travelling speed

20m / min

2.1.2. Runway girder and rail attachment The crane is supported by a welded I-section runway beam with H = 500mm, B = 250mm, t w = 9 . 5mm and t f = 16 mm. The rail is continuously attached to the top flange by fillet welds (rigid fixation assumption in the FE model). Two variants of the web–flange joint are assessed: (i) double fillet welds, and (ii) full-penetration (K) weld.

2.2. Numerical modelling and load-case definition

2.2.1. Crane FE model and wheel reaction extraction A detailed FE model of the overhead crane is created using 2D shell elements in Simcenter Femap with a Nastran solver to obtain realistic wheel reactions under operational conditions. Eight trolley positions are considered to capture the influence of trolley location on wheel-load distribution and torsional response. Combined with the considered operating actions, this yields more than 48 fatigue-relevant load cases for the crane. The resulting wheel reaction components (vertical and horizontal) are extracted for fatigue-relevant cases of crane runway girder. 2.2.2. Runway assembly FE model An FE model of the runway assembly is built with 2D shell elements and includes the runway beam, rail, support columns, and surge connections to account for global sti ff ness and load distribution. Wheel reactions from the crane model are applied directly to the rail. To capture governing stress influence zones, two longitudinal crane positions along the runway are analysed: (i) wheel passage at midspan, and (ii) wheel passage near the support / sti ff ener region around the surge connection. This doubles the number of load cases considered for the crane. The complete model is built with a fine mesh size of no more than txt in critical areas, making it a suitable option based on the mesh convergence study, which is briefly provided in Appendix A. 2.2.3. Definition of fatigue scenarios All loads acting on the structures, load combinations, and dynamic factors used in the analysis are based on the EN 13001 and Eurocode 3 standards with compatible setup. Two scenarios are compared: • Scenario V (vertical-only): only vertical wheel reactions are applied in the runway model. • Scenario VH (vertical + horizontal): vertical and cyclic horizontal reactions from crane drives are applied. Horizontal actions are scaled by a dynamic factor φ 5 representing drive dynamics.