Abstract:Sheet metal in the moving car is widely used in modern design, such as detection of defects has very important significance. For this purpose, the use of ultrasound of multiplicity provide additional data to detect the defects of sheet metal, and the algorithm of multiplicity is predictable path in the direct reflection of the path and identify, directly reflect the path is relatively easy to identify. Using ANSYS finite element modeling different sheet defect model at the same time, the different sensor location, defect location, defect size cases are simulated respectively. Obtained by ANSYS simulation and experimental tests are good results, the error in the range of controlled, proved that the ultrasonic application of multiplicity and sheet metal Lamb wave detection is feasible; Simulation and experiments show that ultrasonic way through actual and virtual extension of multiplicity of sensor data analysis proved that the ultrasonic multiplicity can for detecting sheet to locate defects and their size. Ultrasound of multiplicity of detection method is put forward, through a single measurement can detect the defect size and location of the plate, has good detection performance.