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The paper presents a nondestructive technique for the evaluation of elastic moduli of layered
fiber-reinforced composites. It is based on the minimization of the discrepancy between
the theoretically calculated and experimentally measured dispersion curves of guided Lamb
waves generated by surface-mounted piezoelectric wafer active sensors. Numerical simulation
is performed in the context of 3D linear elastodynamics for anisotropic solids. It relies on
the explicit integral and asymptotic representations derived for the force-generated wave
fields in terms of Green's matrix of the composite structure considered. The minimization
of the least-square error sum between the measured and calculated data is achieved through
a real coded micro-genetic algorithm. The reliability of the proposed approach is experimentally
validated via static tensile tests as well as by the frequency response evaluation.
Keywords: laminate composite; guided waves; group velocities; effective elastic properties; piezoelectric actuators; laser vibrometry |
full paper (pdf, 1344 Kb)