PSI - Issue 38

Jacques Berthellemy et al. / Procedia Structural Integrity 38 (2022) 428–446 Jacques Berthellemy / Structural Integrity Procedia 00 (2021) 000 – 000

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2. Aim of the study Present version of Eurocode EN 1993-1-9 [17] provides a detail category of 71 MPa in the detail n°9 of Table 8.2 for the cope hole at the weld toe according to the stress in the flange. This detail category is present again in the 2020 project of the same Eurocode: Fig. 9.

Figure 9: Detail category according to the Eurocodes The normative Annex D of pr EN 1993‐1‐9 (2020) will provide very useful recommendations for magnification factors k 1 and stress concentration factors k f, that should be taken into account for the calculation of modified nominal stresses. However, present Part D.3 provides these coefficients for flanges of I- s ection girders with transitions in thickness or width only when no cope hole is present. This is a great progress due to Professors H. Unterweger and A. Taras [18]. Without any rules when the cope hole is coinciding with a transition in thickness, the danger of a wrong use of the 71 MPa detail remains, as it was the case in France during the 90’s. The proposed stress concentration factor k f presented here tries to complete these rules. It was obtained by calculation using the hot spot stress method for a height or radius of 60 mm for the cope hole. Today the cope holes coinciding with a transition in thickness are rightly avoided for motorway bridges in several countries. One aim is to avoid with rational rules a complete interdiction of the cope hole when the traffic is not as aggressive as a motorway traffic. In addition, this SCF k f will help for the best rational assessment of existing motorway bridges presenting features similar to those presented in Fig. 10 that were allowed during the '90s.

10-a: Important thickness transition case

10-b: Usual case

Figure 10 : Example of motorway bridge features built in the 90’s with cope hole wrongly calculated without SCF for class category 71 MPa