Large-format additive manufacturing of thermoset composites enables rapid fabrication of large structures, but nondestructive characterization of their print-path-dependent mechanical behavior remains difficult. Existing qualification routes rely mainly on destructive coupon testing or defect-oriented nondestructive evaluation and therefore provide limited capability for targeted mapping of direction-dependent mechanical variability. This study presents a piezoelectric transducer–laser Doppler vibrometry framework for direction-conditioned dispersion inversion of full-field guided wave measurements in additively manufactured thermoset composites. The method decomposes the frequency–wavenumber spectrum by propagation angle and independently fits the extracted dispersion data in each propagation direction to obtain scan-region-specific effective shear-wave velocity, an effective Poisson’s-ratio parameter, and effective-modulus responses as functions of propagation direction. Benchmark testing on an isotropic aluminum plate validates that the workflow recovers isotropic guided wave behavior without introducing artificial angular bias. Applied to a chopped-carbon-fiber thermoset composite, the framework reveals print-path-dependent anisotropic wave propagation through elliptical wavefields and frequency–wavenumber spectra. The resulting effective stiffness estimates reproduce the direction-dependent stiffness variation and approximate magnitude observed in conventional tensile measurements, supporting the mechanical relevance of the guided wave-derived response. By converting full-field guided wave measurements into scan-region-specific, direction-resolved effective-stiffness estimates, this work provides a practical nondestructive route to support quality control, process validation, and structural evaluation of aerospace composite tooling manufactured by large-format thermoset additive manufacturing.

Carbon Fiber Reinforced Polymers (CFRP) are extensively utilized in high-performance engineering, yet localized structural discontinuities can severely compromise their integrity. This paper aims to achieve high-sensitivity characterization of such anomalies using a proposed acoustic shearography technique based on continuous acoustic excitation. A comprehensive finite element model (FEM) was developed to clarify the mechanical-energy coupling between the acoustic fields and localized surface strain field modulations. By exploiting ultrasonic energy coupling, the localized features of discontinuities were identified through full-field, non-contact optical measurement of localized phase distortions. Key parameters, including shearing amount, excitation frequency, driving voltage, and geometric characteristics of blind flat-bottom holes (BFBH), were systematically investigated. The results demonstrate a high correlation between FEM simulations and experimental observations quantitatively elucidating how defect diameter and hole depth modulate surface strain distributions. The proposed hybrid acoustic optical approach achieves near-instantaneous full field imaging within a millisecond timeframe typically under 200 ms. Additionally, the methodology leverages localized acoustic resonance to significantly boost the signal-to-noise ratio (SNR) resulting in highly quantified phase map contrast.