The Finite Element Simulation Of Ultrasonic Wave Propagate In Solid

Main principle of ultrasonic detection is based on a variety of transmissioncharacteristics of the spread of ultrasound in objects to assess the object itself and whetherthere is defect inside. The most advanced ultrasonic detection method at present is phasedarray and TOFD(time of flight diffraction)ultrasound testing. This two methods arepreliminary applied in domestic, but is still in the primary equipment technology studyand popularization stage. In order to promote the development of ultrasonic testingtechnology, two advanced methods of the ultrasonic testing for finite element numericalsimulation are studied in this paper. The purpose of the simulation is aim at the limitationof judgment for defects in the weld detection with TOFD method, the numerical simulationis taken as an auxiliary means contribute to weld detection, and it is great helpful forunderstanding the ultrasonic propagation in solid objectively. In the process of studyingultrasonic testing it will also be more intuitive understood and convenient for testingtechnology promotion and popularization.The system of finite element numerical simulation model in ultrasonic testing processmainly has three parts, ultrasonic probe, wedge and tested specimens, which are needed toestablish mathematical model respectively. Firstly, various wave propagation process weretested in the absence of defects specimens to determine its physical propagation law duringthe whole process. Secondly, testing with TOFD method and phased array methodrespectively in a flawed model. Finally, simulating the ultrasonic propagation andanalyzing the experimental results between the two methods. Simulation results show thatthe echo amplitude accuracy is not high, and very high accuracy of flaw echo time. Thisillustrates the application of numerical simulation of the propagation time can onlymeasure quantitatively the defect TOFD method is feasible. TOFD ultrasonic model isestablished based on Huygens’ principle. From another point of view that the use ofsimulation tools in actual testing aided analysis of the test results is feasible. But the application of ultrasonic TOFD method to get echo amplitude was not high accuracy, hisshortcoming simulation method can also be used to compensate. In practice, the firstnatural defects classification, modeling, especially those aligned longitudinally or verticalnatural defects in the ray inspection cannot be completed, the results of simulationmodeling and experimental results after a high degree of matches, so just shows thenumerical simulation of natural defects detected by TOFD as an adjunct defect detectionmeans is very effective.