Acoustoelastic effects in elastic media with nonuniform initial stress

A perturbative formalism for the treatment of the acoustoelastic effect in material plates with a stress profile in the thickness direction is propose d and compared with a numerical method. The latter consists of an applicati on of the local interaction simulation approach (LISA). The reliability of both the analytical treatment and the numerical approach is tested by compa ring the respective results for several cases of propagation of Rayleigh wa ves in specimens with various kinds of stress fields, including welded stee l plates. Finally, the linearization obtained from the perturbation treatme nt is exploited for the solution of the "inverse problem," i.e., the determ ination of the stress field from a set of RW times of flight with different wavelengths. A numerical example is provided to illustrate the applicabili ty of the method, starting from a set of synthetic data obtained with LISA.