Expert System for Fatigue Design of Spot-welded Joint.

Abstract

In establishing a long life fatigue design criterion and estimating the reliability of spot-welded thin sheet structure such as the automobile and train, it is necessary to estimate fatigue strength of spot-welded joint. So far, many investigators have numerically and experimentally studied on the method of systematic fatigue strength estimation for various spot-welded joint. Also considerable amount of data on the fatigue strength of spot-welded joint has been accumulated. But, it is difficult to determine the fatigue design criterion based on the existing data when fatigue design is modified. Therefore, many tests were required to determine a new criterion for modified design. Then it takes a lot of money and time. Thus, an expert system was developed to predict the fatigue design criterion including fatigue strength and fatigue life of spot-welded joint. The expert system consists of the material destination database, the spot-welding condition database and the fatigue design module. And this expert system was developed based on the knowledge base, the numerical calculation module, interface engine and user interface. It is expected that the expert system can economically provide the designer and the manufacturer with useful information on the material properties and the fatigue design criterion for a modified design.