You-xing CHEN(陈友兴)1,2, Zhao-ba WANG(王召巴)1,2, Yong JIN(金永)2, Ji-liang YANG(杨继亮)1,2
(1. National Key Laboratory for Electronic Measurement Technology, North University of China, Taiyuan 030051, China; 2. Key Laboratory of Instrumentation Science & Dynamic Measurement（North University of China）, Ministry of Education, Taiyuan 030051, China)
Abstract-A metal rod is used in the high temperature testing for ultrasonic propagation and heat output, but the trailing echoes 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 ultrasonic propagation in a metal rod is established and calculated, then the simulation signals and instantaneous cartographies of the process are obtained. Based on the results of the analysis, it can be concluded that the intervals of the trailing echoes are determined 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 adjusted and selected, aiming to identify the characteristic echo and trailing echoes in time domain and extract characteristic echo from the ultrasonic signals available.
Key words- ultrasonic propagation; FEM; finite rod
Manuscript Number: 1674-8042(2011)04-0312-05
doi: 10.3969/j.issn.1674-8042.2011.04.002
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