Dispersion curve estimation via phased array beamforming methods

Localization of scattering sources via active ultrasonic inspection in plate-like structures requires knowledge of the structure’s dispersion relation and material properties. Often the dispersion relation and material properties are unknown, uncertain, or difficult to model due to material complexity and variability in material properties, geometry, and/or environment, thereby requiring in situ estimation. Two methods are presented for estimating guided wave dispersion curves (phase and group velocity) in a multimodal, multipath environment using a phased array. Phase and group velocities are estimated in situ on an aluminum and carbon fiber plate and compared to theoretical values. Scattering from plate boundaries is localized using the estimated phase and group velocity curves through beamforming and ranging via time of flight.