Guided waves generated and measured using surface-bonded Lead Zirconate Titanate (PZT) transducers have been
widely used for structural health monitoring (SHM) and nondestructive testing (NDT) applications. For selective
actuation and sensing of Lamb wave modes, the sizes of the transducers and the driving frequency of the input waveform
should be tuned. For this purpose, a theoretical Lamb wave tuning curve (LWTC) of a specific transducer size is
generally obtained. Here, the LWTC plots each Lamb wave mode' amplitude as a function of the driving frequency.
However, a discrepancy between experimental and existing theoretical LWTCs has been observed due to little
consideration of the bonding layer and the energy distribution between Lamb wave modes. In this study, calibration
techniques for the theoretical LWTCs are proposed. First, a theoretical LWTC is developed when circular shape of PZTs
is used for both Lamb wave excitation and sensing. Then, the LWTC is calibrated by estimating the effective PZT size
with PZT admittance measurement. Finally, the energy distributions among symmetric and antisymmetric modes are
taken into account for better prediction of the relative amplitudes between Lamb wave modes. The effectiveness of the
proposed calibration techniques is examined through numerical simulations and experimental estimation of the LWTC
using the circular PZT transducers instrumented on an aluminum plate.