Composite material defect recognition based on fuzzy theory in ultrasonic testing

Based on signal of compound materials defect such as lamination,hole, loosening in ultrasonic testing,defect signal characteristic parameter in time domain and the frequency domain are selected in the paper.Considering coupling relations between various characteristic parameters and importance and sensitivity in pattern recognition,we structure membership function inclusion weight coefficient according to polyhedron degree of membership concept,and distinguish compound materials defect type by biggest subordination principle.