Near Field Effects and Estimation of Poisson's Ratio in Impact-Echo Thickness Testing
Based on the polarization and shape of the first symmetric Lamb mode at the zero-group velocity point (S1-ZGV), a novel approach for Impact-Echo thickness testing is proposed. In this new approach all three plate parameters (thickness, velocity and Poisson's ratio) are estimated from the same wave mode (S1-ZGV). A traditional approach based on a measurement of the longitudinal-and Rayleigh wave ve