Hybrid expert system for the failure analysis of mechanical elements

An expert system for the failure analysis of metallic mechanical components is described, with emphasis on the structure and the solution strategy followed by the software. The system treats failure in common mechanical elements and is aimed to guide non-experts through the process of basic failure analysis. The system acts as a “virtual colleague”, providing guidance and experience during failure studies. As such, it allows the users to gradually increase their experience while using the software in distinct applications. The system works interactively through a system of structured questions. The answers provided by the user permit the software to direct the analysis toward its solution. Decisions are taken in a hybrid way, through case based reasoning and rule based reasoning, the former using a database of solved cases, the latter mimicking the way experts treat failure analysis. The paper describes the development method, the logic behind the operation of the system and the interaction between case based reasoning and rule based reasoning modules. Its performance in four real-world failure cases is used to demonstrate its feasibility and usefulness.