Structural Safety and Integrity Assessment and Use of Expert Systems at MPA Stuttgart

Abstract

The paper gives a condensed review of current activities and research programs of MPA Stuttgart in the domain of structural safety and integrity assessment, and of the efforts directed towards the development and application of the related expert systems. The above mentioned activities are mostly related to pressurized nuclear and non-nuclear components. A large part of the research work has been performed within the scope of the Reactor Safety Research and Development Program of the German Federal Ministry for Research and Technology (BMFT). This program started in the early seventies, involving large scale experiments and analytical research. Issues like leak-before-break or pressurized thermal shock can be mentioned as the typical ones. The problems of fracture, crack initiation, crack propagation and crack arrest have been investigated, under simulated operational conditions, corresponding to the real ones in terms of internal pressure, temperature, corrosion, etc., which has been of decisive importance for the transferability of the test results to real components. In addition, a series of complementary issues has been investigated (material science aspects, nondestructive examination, etc.). Application of artificial intelligence, i.e. of expert systems, is one of these complementary activities, aimed at improving the actual possibilities to assess safety and integrity of structural components. The development and application of expert systems required first the definition of a general framework, i.e. of the environment for development of expert systems, as well as the identification of the specific practical application sub-domains. The modular structure of the framework and the first application sub-domains (leak-before-break analysis and high temperature pressurized components) are briefly outlined.