The influence of stresses resulting
from weld misalignment in cylindrical shell circumferential weld joint on the
shell integrity has been considered. The stresses have been estimated
analytically by API recommended practice 579 procedure and calculated
numerically by using the finite element method.
Surface circumferential crack has been
assumed perpendicular to the principal stress at the location of maximum stress.
Failure assessment procedure has been performed for the most dangerous situation
(e = 8 mm) varying the crack depth to thickness ratio as a/t =
0.4; 0.45 and 0.5. Critical internal pressure values for these cases have been
found by using of FAD diagrams.
Keywords: cylindrical shell, weld misalignment, stresses, API 579, finite
element method, surface circumferential crack, failure assessment diagram (FAD)