Development of Expert System for Estimation of Weld Flaw by Ultrasonic Testing.

Abstract

Development of an expert system for ultrasonic testing can contribute to improvement and standardization of inspection level if the technique and experience of the UT engineer can be incorporated as the knowledge database. Then, it is considered that such an expert system will be a way to solve the shortage of UT engineers in the near future. The present system has been originally developed as a system having a knowledge base system and inference engine which are combined with a blackboard model and frame model. In the developed expert system, which is unified with a man-machine interface, it may be advantageous to use a production rule and a forward inference. The inference was performed in two steps. The candidates for weld flaw were firstly inferred from the welding condition, and then the final flaw was determined from the UT data. When the present expert system was applied to diagnosis of the weld flaw of the welding structure, the results obtained by the present system agreed with those obtained by the UT engineer up to about 90%. It can then be confirmed that the expert system is available as a method of inference for weld flaws, using ultrasonic testing data.