Abstract: Fuzzy neural networks fault diagnosis technology and diagnosis mode are used to diagnose cracks. The fuzzy neural networks are trained with promoted BP arithmetic. The faults of cracked cantilever plate are diagnosed using the trained fuzzy neural networks. Firstly the mode and frequency of numerical simulation intact plate and different cracked plates are calculated. Then five crack diagnosis indexes are calculated. Divide five indexes into three groups and create three fuzzy neural networks. The fuzzy neural networks are trained using these indexes, and diagnosis is taken to the crack in the end. Compared the diagnosis result with the actual crack and an effective result is gotten.

Key words: Crack, Fault diagnosis, Fuzzy neural networks