PSI - Issue 79

Martin Sladký et al. / Procedia Structural Integrity 79 (2026) 421–432

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CHS lap

CHS fillet

Plate-RHS fillet

CHS-Plate fillet S

CHS-Plate fillet G

RHS fillet IPB

RHS fillet OPB

Plate fillet T Ben

Plate fillet T Ten

Plate fillet L

Fig. 2. Thin-walled fillet-welded specimen configurations analyzed in this study and tested in the as-welded condition, with fatigue cracks initiating predominantly at the weld toe.

specimens were tested at frequencies between 2 and 10 Hz, with the exception of the Plate fillet T Ten configuration, which was tested at a significantly higher frequency of 240 Hz.

2.2. Numerical Stress Analysis

Since nominal stress can be determined using simple analytical expressions, this subsection focuses on evaluating hot-spot and notch stresses using finite element simulations. All the simulations assumed purely linear elastic material behavior, in accordance with Hobbacher and Baumgartner (2024). An assessment of potential geometric nonlinearities confirmed that large deformation e ff ects are negligible across all specimen configurations. Consequently, the only nonlinearities accounted for in the simulations arose from contact interactions, namely the general contact between the loading pins and the outer tubes of the CHS-fillet specimens, and the rigid body contact between the bottom plate of the CHS-Plate fillet specimens and the supporting frame.