PSI - Issue 38

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

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2.1. Parameters influencing the transition in thickness

By convention the class of reference with 71 MPa of the detail n°9 of Table 8.2 of EN 1993-1-9 [17] is conserved and as a consequence, stress concentration factors have to be applied. Three risks of crack initiation have to be considered as presented in Fig. 11: 1- kf is the stress concentration factor for the plate. 2- kc is the stress concentration factor at the hot spot along the cut. 3- The web and the flange are butt-welded in the transition zone at both sides of the cope hole along a total minimal length of 1,75 x lt. The web-flange interaction is more difficult to model by FEM but the tension perpendicular to the fillet weld could be deduced from the signed von Mises presented in Fig. 3. The use fillet welds would lead to a very painful stress concentration factor at weld toe that should be confirmed by additional tests. The governing parameters that influence as well k f and kc are : t 2 / t 1 : Ratio of the plate thicknesses at the transition  /  : Ratio of the shear stress in the web to the longitudinal stress in the flange t 1 is supposed to verify t 1 > 16 mm l t is the transition zone length and transition slope is ≤ 1/4 Height (or radius) of the cope hole is ≤ 60 mm

Figure 11 : Determinant parameters