Multiaxial fatigue assessment of welded joints using a principal component-based measure for non-proportionality

Non-proportional multiaxial stresses in welded structures cause higher fatigue damage than proportional stresses. In this paper, a new approach based on principal component analysis for quantifying the level of non proportionality in stress signals is developed. The quantifier is developed for large-scale structures (civil and offshore structures), where the influence of mean stresses is negligible. The proposed quantifier is compared and validated with other approaches from literature with the relevant fatigue criteria and experimental data. The results show that the proposed principal component-based quantifier can capture the level of non-proportionality accurately, which can be used for accurate fatigue life estimations.

Automated summary

A new approach based on principal component analysis is developed in this paper to quantify the level of non-proportionality in stress signals in welded structures. The proposed approach accurately captures the level of non-proportionality and can be used for accurate estimation of fatigue life.