Parametric Inversion of Material Based on Genetic Algorithm and Target Echo Characteristics.

Dispersion equation of Lamb wave in underwater elastic plate coated with viscoelastic damping layers is derived, and the phase velocity and attenuation coefficient of Lamb wave propagating in the submerged composite plate at different frequency-thickness products are obtained under the condition of certain elastic modulus. The phase velocities and attenuation coefficients of the first two Lamb wave modes propagating in the composite plate at certain frequency-thickness product are measured by the echo measurement experiment of submerged elastic plate coated with viscoelastic damping layers, the elastic modulus of viscoelastic material is then inversed by substituting the experimental results into the dispersion e-quation. The results show that the phase velocity and attenuation coefficient of composite plate, and the inversed elastic modulus of viscoelastic material coincide with the theoretical values well, error in experiment less than four percent, it's proved to be feasible to inverse elastic modulus of viscoelastic material based on genetic algorithm and echo characteristic. [ABSTRACT FROM AUTHOR]