Fuzzy Sets and Structural Engineering

Abstract

The process of accounting for subjective information, insight, and wisdom in structural engineering decision making is a matter of debate. One effort to include verbal ideas involves the use of the fuzzy set theory. This paper may be considered as a primer for applications in structural engineering. The first part provides a justification for the theory and then simple fuzzy operations are developed and contrasted with those of conventional set theory. Two applications are then developed. The first considers the fuzzification of objective information where cylinder test results on concrete are used as a basis for the evaluation of the actual strength in a structural member. The two may not be the same and the subjective argument to assess the concrete strength of the beam is treated by fuzzy logic. The second concerns an engineer's assessment of the damage to a structure and subsequent repairs. Here a plan for starting such a problem is provided within a rule‐based assessment system called SPERIL version I. Finally, some of the problems of practical fuzzy set analysis are analyzed and then placed in a general scheme for uncertainty identified.