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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5. Illustrated Tables of results in Annexes The figure 8 presents the results for the example corresponding to a load with  = 0,10 and the geometry with t 2 / t 1 = 1,667. The web is painted with the probability of crack initiation along the cut and the flange is painted with the governing principal stress. All the other results follow in the tables in annex, except for t 1 to avoid an unnecessary accumulation of pictures.

Figure 18 : Commented view of an example of the results presented in the following tables

6. How to repair and conclusion The proposed rules for the cope holes construction detail allow to calculate and build more durable bridges. However, once a bridge is in service, site strain measurements under well known calibration test loads as well as under the existing traffic can also be made. It is possible to evaluate in this way the set of stresses at the details that can be at the location of a crack initiation. The assessment of old wrong hope hole details will then be easy using the presented rules to achieve maintenance actions, accurate to the needs of the society. When the existing cope hole is a critical hot spot of the structure, the repair may consist in preparing and welding a small piece of a puzzle to complete the web in the hole that was cut with a 60 mm radius. The residual stresses resulting from this repair will be less than a filling of the hole with welding materials. It is not recommended to have a HFMI treatment of existing fillets welds in the transition zone because the cracks can initiate at the welds roots, where HFMI does not help. If needed, the fillet weld between the flange and the web in the transition zone can therefore be replaced after grinding by a butt weld connexion at this occasion. However, HFMI may of course be used to reduce the residual stresses that occur with these repairs on an existing restrained structure as presented in [30,31]. The history concerning how to think about the cope-hole demonstrates the need to pay attention to details in order to insure the durability of the steel bridges.