Love Waves Propagation In Graded Materials

At present, study of Functionally Graded Materials is paid more and more attenction by people. So parameter identification for Functionally Graded Materials appeals more important. Because the change of mechanical parameters of Functionally Graded Materials has a obvious effect on the law of Love waves propagation in the materials, Functionally Graded Materials parameters can be identified by the law of Love waves propagation. The study of this paper can provide early theoretical basis for parameter identification, which has serious theoretical and realistic significance.This paper studies Love waves propagation in a Functionally Graded Materials half-space by theoretical derivation. The differential equation with varied coefficient is solved and then the analytical solutions of displacement of Love waves are obtained. The general form of Love waves dispersion equation is educed by these analytical solutions. The properties of Functionally Graded Materials whose shear modulus and mass density are gradually varing in some form are calculated and analyzed and the curves of Love waves dispersion are obtained. Meanwhile, the material parameters effects on wave velocity and cut-off frequency are discussed.The anti-plane shear waves propagation in homogeneous materials and Functionally Graded Materials is simulated and calculated by using finite element method. The results show that the propagation law is consistent when the wave propagates at different zones in the homogeneous model. However the propagation law is diverse in Functionally Graded Materials model. The calculation results are compared and analyzed and then the law of amplitude change with time is obtained when the wave propagates at different zones in Functionally Graded Materials model. The curves of amplitude change is ploted and the curves are compared and analyzed. The results show that the law of amplitude change is affected by frequency and Functionally Graded Materials parameter when the wave propagates in Functionally Graded Materials.