PSI - Issue 77

Enrique Gómez et al. / Procedia Structural Integrity 77 (2026) 49–55 Enrique Gómez et al. / Structural Integrity Procedia 00 (2026) 000–000

52 4

= =

(2)

(3)

Table 2. Maximum tensile stresses in the inner shell (through-thickness and surface locations). NOC. Load case Radial stress (MPa) Circumferential stress (MPa) Axial stress (MPa) Thickness Surface Thickness Surface Thickness Surface Corner drop bottom 3.8 4.9 6.0 Corner drop lid 9.3 3.3 14.4 31.9 Horizontal drop 5.5 2.4 9.9 38.6 Vertical drop bottom 3.8 2.4 4.6 6.0 Vertical drop lid 6.8 4.2 26.2 28.7 Table 3. Maximum tensile stresses in the inner shell (through-thickness and surface locations). AC. Load case Radial stress (MPa) Circumferential stress (MPa) Axial stress (MPa) Thickness Surface Thickness Surface Thickness Surface Corner drop bottom 6.1 14.0 20.7 Corner drop lid 25.8 34.5 60.1 Horizontal drop 18.1 62.3 140.0 Oblique drop 6.2 54.2 57.3 Vertical drop bottom 4.4 12.3 18.1 Vertical drop lid 12.2 64.9 43.8 Bottom puncture 1.4 33.9 45.1 Lid puncture 7.5 79.5 162.2 Ring puncture 85.6 58.4 320.8 289.8

K I (stress intensity factor) solutions are those gathered in BS7910 Annex M for plates containing surface and embedded flaws, whereas σ ref solutions are those gathered in BS7910 Annex P for the same type of defects. The position of the assessment point within the FAD determines whether it is operating under safe conditions (point below the Failure Assessment Line, FAL) or unsafe conditions (point above the FAL). K mat in equation (2) is given by equation (1). Finally, the equations defining the Failure Assessment Line (materials exhibiting yield plateau) are the following: ( )= � 1+ 1 2 2 � −1 / 2 for L r < 1 (4) ( )= � + 21 � −1 / 2 for L r = 1 (5)