The project is aimed firstly at developing a theoretical framework for the ultrasonic non-destructive evaluation and characterisation of nonlinear material properties, and of the pre-stress associated with large deformations in elastic solids. The theory depends on the fact that only certain directions in a deformed solid admit pure transverse or longitudinal waves. Identification of such directions and the corresponding wave speeds will provide a basis for comparison of the theory with experimental data. Recent joint work by the applicant and hosts offers scope for considerable development, and will also be adapted to provide information on the integrity of bonding in, for example, layered media.
The second main aim ofr the project is to contribute to the analysis of the influence of pre-stress on nonlinear wave propagation (particularly near points of instability), understanding of which is important for the interpretation of the results from the first part of the project.