Inverse characterisation of the dynamic properties of fully anisotropic, anelastic materials

The objective of the current proposal is to study methods for inverse characterisation of acoustic porous materials with anisotropic and anelastic properties.

This is performed in a combination of computational homogenisation, based on full field 3D dynamic displacement data, and numerical prediction models, enabling the identification of the dynamic behaviour of real materials.

The first stage of the project will focus on the inverse modelling itself, including aspects of elastic, dynamic and computational homogenisation.

Recent advances in the identification of anisotropic elastic properties of cellular materials will form the basis for addressing the dynamic problem.

One of the main challenges in the dynamic problem is to ensure that the micro-fluctuations of the displacement fields of the cell structure are considered at the macro-scale where the dynamic properties are determined.

For this purpose different means of augmenting a known equivalent elastic material model will be studied, e.g. using a series of relaxation terms each with their own anisotropy, or using a higher order continuum representation with second gradients of the displacements.The proposed research entails several fundamental material modelling issues which have so far not been thoroughly addressed for dynamic modelling of materials with anisotropic elastic properties.