Development and Improvement of Numerical Models of Welded Joints with Multiple Defects

Abstract

This paper presents the development of numerical models which were used to simulate the behaviour of welded joints containing different combinations of multiple defects under tensile loads. Four representative combinations of defects were selected (including undercuts, incomplete root penetration, misalignments...), based on practical experience. In order to create accurate and functional models, this research involve a number of stages. This paper will focus on the various improvements made to the models, which started in relatively simple form. For this purpose, initial experimental and numerical analyses were carried out on specimens made of low-alloyed low-carbon steel S235, and after their accuracy was verified, the same methodology was applied to specimens made of higher quality material, steel S275. Improvements made to the models involved geometry, different combinations of boundary conditions and loads, and some were based on stress-strain states obtained by a combination of tensile testing and digital image correlation. The final result was a set of detailed numerical models which accurately simulated the behaviour of welded joints with multiple defects in them.