ANFIS Lamb wave Love wave analytical solution attenuation bimodulus circular plate clustering combined mechanical loads damping coefficient different moduli in tension and compression dispersion elastic foundation elastoplastic analysis electroelastic solution elliptical hole evanescent wave external pressure failure and damage finite element analysis finite element method finite elements flow theory of plasticity free vibration characteristics functional graded saturated material functionally graded beams functionally graded materials functionally graded piezoelectric materials functionally graded piezoelectric-piezomagnetic material functionally graded plate