PSI - Issue 77

João Nuno Silva et al. / Procedia Structural Integrity 77 (2026) 657–664

663

Joa˜o Nuno Silva et al. / Structural Integrity Procedia 00 (2026) 000–000

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component making a negligible contribution. The multiaxial combinations in EN 1993-1-9 standard and the IIW Recommendations amplify this dominant component, leading to the highest combined values among these approaches. In contrast, railway-focused codes (DVS 1612 code and EN 17149-3 standard) evaluated the joint with a safety margin under their respective multiaxial criteria. For Weld 2 (case b), every approach across, except the ERRI B 12 / RP60code, remains below the verification limit. Weld 3 (case c) is non-critical across all criteria, with all components well below the verification limit. Weld 4 (case d) again shows ERRI B 12 / RP60 code as the most demanding check. This outlier behaviour is consistent with ERRI B 12 / RP60 code, higher target reliability (infinite-life check at 99.7% survival probability), and its critical plane method based on principal-stress projections. The fatigue design verification methodologies of these codes vary markedly. DVS 1612 code and EN 17149-3 standard o ff er railway-specific catalogs of welded details and resistance classes tailored for carbody construction, enabling refined assessment of joint geometry relative to operational demands. In comparison, EN 1993-1-9 standard and the IIW Recommendations provide generic guidance for metallic structures, while ERRI B12 / RP60 remains the most general, subdividing components into five basic notch cases. Both methods in DVS 1612 and EN 17149 3 explicitly incorporate weld performance class (EN 15085-3), inspection class, thickness corrections, and material grades on the resistance side. Moreover, EN 17149-3 introduces an extended set of resistance-modifying factors, as summarised in Section 2.4.

Table 1: Utilisation factors, U f , by design code and criteria for four welded joints, according to several design codes.

Design code

U f ∥

U f ⊥

U f τ

U f , multi

Weld 1 ERRIB12 / RP60 a

– –

–

–

1.07 1.47 1.30 0.84 0.94 1.18 0.26 0.47 0.68 0.56 0.54 0.16 0.25 0.19 0.29 1.11 0.07 0.20 0.58 0.58

EN 1993-1-9 b

1.14 1.14 0.93 0.94

0.07 0.07 0.11 0.06

IIW Recommendations b

0.57 0.05 0.08

DVS1612 c EN17149-3 d

Weld 2 ERRIB12 / RP60

– –

–

–

EN 1993-1-9

0.36 0.38 0.30 0.39

0.00 0.00 0.00 0.00

IIW Recommendations

0.57 0.92 0.56

DVS1612 EN17149-3

Weld 3 ERRIB12 / RP60

– –

–

–

EN 1993-1-9

0.55 0.48 0.42 0.27

0.12 0.12 0.27 0.09

IIW Recommendations

0.06 0.23 0.06

DVS1612 EN17149-3

Weld 4 ERRIB12 / RP60

– –

–

–

EN 1993-1-9

0.01 0.01 0.24 0.01

0.0

IIW Recommendations

0.45 0.76 0.58

0.07 0.11 0.08

DVS1612 EN17149-3

a Haigh diagram for 99.7% survival probability c MKJ diagram for 97.5% survival probability

b S-N curve for 95% survival probability d S-N curve for 97.5% survival probability