This paper deals with the application of Acousto-ultrasonics,in con- junction with Pattern Recognition and Classification techniques,to the identification of residual impact properties of a class of polymeric material...This paper deals with the application of Acousto-ultrasonics,in con- junction with Pattern Recognition and Classification techniques,to the identification of residual impact properties of a class of polymeric material,namely,Polyvinylchlo- ride(PVC).PVC specimens of different low-energy repeated impact damage states are processed by Acousto-ultrasonics(AU)to retrieve AU signals in the form of dig- italized records.These AU signals are grouped as distinct classes,each pertaining to a known level of repeated impact damage.Describing features of these AU signals are used to build Pattern Recognition(PR)Classifiers.These classifiers are used to identify unknown damage states in other PVC specimens by classifying the re- trieved AU signals as belonging to one of the classes.The obtained results indicate that Acousto-ultrasonics in combination with Pattern Recognition and Classification techniques can be used for the quantitative non-destructive identification of damage states in PVC specimens of unknown low-energy repeated impact conditions.展开更多
in the acousto-ultrasonic technique, a broadband ultrasonic wave is injected onto the surface at one location of the tested plate with the help of a longitudinal transducer and a receiving transducer is coupled to the...in the acousto-ultrasonic technique, a broadband ultrasonic wave is injected onto the surface at one location of the tested plate with the help of a longitudinal transducer and a receiving transducer is coupled to the same surface at another location. Thus, understanding the propagation characteristics of the ultrasonic wave is essential for successful application of the technique. It has been found that the dominant acousto-ultrasonic waves produced experimentally in thin plate are multi-mode Lamb waves. The broadband generation and detection of Lamb waves have been performed in two aluminum plates with different thickness using the acousto-ultrasonic method.展开更多
文摘This paper deals with the application of Acousto-ultrasonics,in con- junction with Pattern Recognition and Classification techniques,to the identification of residual impact properties of a class of polymeric material,namely,Polyvinylchlo- ride(PVC).PVC specimens of different low-energy repeated impact damage states are processed by Acousto-ultrasonics(AU)to retrieve AU signals in the form of dig- italized records.These AU signals are grouped as distinct classes,each pertaining to a known level of repeated impact damage.Describing features of these AU signals are used to build Pattern Recognition(PR)Classifiers.These classifiers are used to identify unknown damage states in other PVC specimens by classifying the re- trieved AU signals as belonging to one of the classes.The obtained results indicate that Acousto-ultrasonics in combination with Pattern Recognition and Classification techniques can be used for the quantitative non-destructive identification of damage states in PVC specimens of unknown low-energy repeated impact conditions.
基金National Natural Science Foundation of China Thans-Century Training Programme Foundation for the Talents by the State Educat
文摘in the acousto-ultrasonic technique, a broadband ultrasonic wave is injected onto the surface at one location of the tested plate with the help of a longitudinal transducer and a receiving transducer is coupled to the same surface at another location. Thus, understanding the propagation characteristics of the ultrasonic wave is essential for successful application of the technique. It has been found that the dominant acousto-ultrasonic waves produced experimentally in thin plate are multi-mode Lamb waves. The broadband generation and detection of Lamb waves have been performed in two aluminum plates with different thickness using the acousto-ultrasonic method.
