An inexact inference for damage assessment of existing structures

Abstract In structural engineering practice, situations exist where the available information is inexact or imprecise. Frequently, experienced structural engineers are capable of providing meaningful answers to such problems. The purpose of this investigation is to construct an expert system called SPERIL-II for the damage assessment of existing structures on the basis of the knowledge of experienced structural engineers. SPERIL-II is a knowledge-based damage assessment system in which there are the following three steps in the assessment process: ( 1 ) the evaluation of local damageability from input data, (2) the evaluation of global damageability, (3) the estimation of the safety or damage state of the structure. This paper introduces an inexact inference using AND/OR/COMB relation and Dempster's rule of combination to combine two fuzzy sets with certainty factors. This inexact inference is used in all steps, and a suitable measure is given according to the importance of the structure in step (3).