DAPS: Expert System for Structural Damage Assessment

Abstract

Assessment of structural damage is a complex subject imbued with uncertainty and vagueness. This complexity arises from the use of subjective opinion and imprecise numerical data. An analysis of the structural integrity of a buried concrete box structure is accomplished using combined nonnumeric and numeric information. Expert opinions on structural damage are used to develop the nonnumeric portion of the code. Fuzzy sets are used to quantify linguistic variables since this type of information is inherently vague and imprecise. Because of the size and the complexity of the problem, a numerical method in the form of a fuzzy weighted‐average algorithm is used instead of rules to synthesize the nonnumeric information. The damage assessment paradigm is subdivided into smaller problems, which in turn are represented in antecedent‐consequent pairs as rules. These rules and numerical data form the knowledge base. The processing of this information is controlled through an expert system shell, which retrieves necessary facts from the user and the knowledge base using an appropriate search strategy. Numeric data are manipulated in the expert system through calls to external subroutines and data bases. This information is then interpreted through the use of production rules.