Structural integrity assessment of welded joints using fracture mechanics parameters and risk based approach

Abstract

Structural integrity assessment of welded joints is presented, based on calculation of fracture mechanics parameters and risk analysis by using risk matrix, with an aim to improve safety of welded structures. As a case study, pressure vessel is presented, with crack-like defects, non-acceptable according to standard. Linear elastic fracture mechanics parameter, the stress intensity factor, Ki, was determined by the conservative and simplified procedure, whereas its critical value, the fracture toughness, was taken from previous experimental investigations. Plastic collapse was also taken into account to construct the Failure Assessment Diagram and to estimate failure probability, so that risk matrix can be obtained knowing also the consequence of failure.