A metal rod is used in the high temperature testing for ultrasonic propagation and heat output, but the trailing ech- oes generated by ultrasonic penetration through the metal rod seriously affect the recognition and ...A metal rod is used in the high temperature testing for ultrasonic propagation and heat output, but the trailing ech- oes generated by ultrasonic penetration through the metal rod seriously affect the recognition and extraction of characteristic signals. According to the phenomenon, the Finite Element Method （FEM） is used to analyze ultrasonic penetration through a metal rod, the reason of the trailing echoes and the regularity of ultrasonic signals. The motion equation of ultra- sonic propagation in a metal rod is established and calculated, then the simulation signals and instantaneous eartographies of the process are obtained. Based on the results of the analysis, it can be concluded that the intervals of the trailing echoes are de- termined by the rod＇ s diameter and wave velocity. In practical applications, the FEM is used to analyze ultrasonic propagation in the designed buffer rod at first. Based on the characteristics of the simulation signals, the material and dimension are ad- justed and selected, aiming to identify the characteristic echo and trailing echoes in time domain and extract characteristic echo from the ultrasonic signals available.展开更多
基金supported by the National Natural Science Foundation of China(No.60672005)the Shanxi Provincial Foundation for Returned Scholars(Main Program),China(No.69)the Science Programof Shanxi Province,China(No.20110321029)
文摘A metal rod is used in the high temperature testing for ultrasonic propagation and heat output, but the trailing ech- oes generated by ultrasonic penetration through the metal rod seriously affect the recognition and extraction of characteristic signals. According to the phenomenon, the Finite Element Method （FEM） is used to analyze ultrasonic penetration through a metal rod, the reason of the trailing echoes and the regularity of ultrasonic signals. The motion equation of ultra- sonic propagation in a metal rod is established and calculated, then the simulation signals and instantaneous eartographies of the process are obtained. Based on the results of the analysis, it can be concluded that the intervals of the trailing echoes are de- termined by the rod＇ s diameter and wave velocity. In practical applications, the FEM is used to analyze ultrasonic propagation in the designed buffer rod at first. Based on the characteristics of the simulation signals, the material and dimension are ad- justed and selected, aiming to identify the characteristic echo and trailing echoes in time domain and extract characteristic echo from the ultrasonic signals available.
