Linguistic assessment of welded structures with fatigue damage

Abstract

Frequently in fatigue damage assessments of welded structures, the available information includes linguistic descriptions of the damage and numerical results from tests and analyses. The precision of the numerical results and the precision of the linguistic descriptions may be inconsistent. However, the incorporation of both types of information is important for a meaningful assessment of structural damage. A linguistic damage assessment technique is presented to incorporate both forms of information into the assessment procedure. The variables used in the assessment are described with linguistic terms that are represented with fuzzy membership functions. A damage assessment function is then determined using fuzzy quantification theory and is used to determine the damaged state. A criterion function is proposed to determine the effects of procedural variables on the assessment function. Finally, the technique is demonstrated using experimental data on the effects of slag inclusions in welded joints.