Development of the Measurement System of Leaky Lamb Waves Dispersion Curves Based on LabVIEW

In this paper, an automatic measurement system of leaky Lamb waves dispersion curves based on Lab VIEW is developed. In this system, the PVDF line-focus transducer is controlled to defocus through the movement of the linear stage, and the NI PXI-5154 digitizer is controlled to acquire echo signals, then the calculation program is called to process the echo signals for calculating phase velocities of measured leaky Lamb wave modes. Two stainless steel samples of 5 mm and 0.5 mm in thickness are experimentally tested by using this developed system. Up to five modes of leaky Lamb waves can be identified. The results are consistent with the theoretical values. The dispersion curves of leaky Lamb waves can be traced automatically through this system.