Analysis of microgeometrical parameters of butt and fillet welds in structural assemblies

Abstract

The values of weld toe angles and weld toe radii in the butt and fillet welds produced by different welding procedures have been analyzed. The aim of the study is to determine the generalized mean values, standard deviations and lognormal distributions parameters of weld toe angles and radii for butt and fillet welds produced by SAW, MMA, and CO 2 welding. Based on the results of weld toe radii and angles measurements published in the literature for sheet thickness and steels with mechanical properties typical to ship structures generalized samples were compiled and statistically processed. Each generalized sample corresponded to a specific type of weld and welding procedure. The influence of welding position as well as some other factors, which can influence on investigated values in generalized samples, was neglected due to the small number of the measurement results. The influence of the mentioned factors on the investigated values and their magnitudes in the expected points of the fatigue crack initiation were studied separately. The largest weld toe radii were in butt welds produced by MMA welding. The obtained generalized mean values, standard deviations and lognormal distributions parameters of weld toe angles and weld toe radii allow us to approximately describe microgeometry of butt or fillet welds and may be used for estimation of the stress concentration in the ship structure welded assemblies and for the fatigue strength analysis of these assemblies.