Knowledge-based system for the computer aided design of ingot casting processes

The complexity of the design in thermal manufacturing processes stems from the need to simulate complicated heat transfer, fluid flow and phase change phenomena and couple the results with the design rules and knowledge available of these processes to obtain satisfactory designs. In this regard, the ability of expert systems to use heuristic reasoning has proved to be a powerful tool in the computer-aided-design of thermal manufacturing systems. In this paper, the salient features of a knowledge-based system developed for the design of the ingot casting process has been outlined. A Prolog-based decision-making front-end is interfaced with a Fortran-based computational engine for rapid design. The results from the heat transfer analysis, obtained from the computational module, are coupled to the evaluation module, which checks for satisfaction of the design critera and violation of the design constraints. The decision-making module uses a set of design rules to manipulate the variables until the design specifications are satisfied. Modularity and flexibility are maintained using an object-oriented format. Several interesting design acceleration features like design inheritance from simpler models and design extraction from previous designs are illustrated. The main features of this knowledge-based tool and the savings in time resulting from using these special features are discussed in detail.