Vol.10, No2, 2010, pp.153-159
UDC  : 621.791.05 : 66-988

WELD MISALIGNMENT INFLUENCE ON THE STRUCTURAL INTEGRITY OF CYLINDRICAL PRESSURE VESSEL

Dražan Kozak, Pejo Konjatić, Franjo Matejiček, Darko Damjanović

J.J. Strossmayer University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Croatia

Abstract

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)

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