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Abstract: This paper reports simulations of the generation of Lamb wave modes in thin plates using a meander coil (meander line) EMAT, which works under the principle of Lorentz force mechanism in non-magnetic materials. The numerical simulations have been compared with measurements. The numerical work presented in this paper is divided into two parts. First, a 2D electromagnetic model is developed for calculating the Lorentz force density, which is the driving force for elastic wave generation within the plate. Second, the calculated force at each point in the metal is used as the driving force for generating elastic wave modes in the plate. These calculated Lamb wave modes are compared with those generated experimentally in a thin plate. Additionally, the measured wave modes are analyzed with the help of dispersion curves and a time–frequency analysis. Our numerical work is also extended to analyze the interaction of Lamb wave modes with defects. The simulations compare favorably with the measurements presented here. [Copyright &y& Elsevier]

Excitation and propagation of Lamb waves by using rectangular and circular piezoelectric transducers surface-bonded to an isotropic plate are investigated in this work. Analytical stain wave solutions are derived for the two transducer shapes, giving the responses of these transducers in Lamb wave fields. The analytical study is supported by a numerical simulation using the finite element method. Symmetric and antisymmetric components in the wave propagation responses are inspected in detail with respect to test parameters such as the transducer geometry, the length and the excitation frequency. By placing only one piezoelectric transducer on the top or the bottom surface of the plate and weakening the strength of one mode while enhancing the strength of the other modes to find the centre frequency, with which the peak wave amplitude ratio between the S0 and A0 modes is maximum, a single mode excitation from the multiple modes of the Lamb waves can be achieved approximately. Experimental data are presented to show the validity of the analyses. The results are used to optimize the Lamb wave detection system. [ABSTRACT FROM AUTHOR]