Non-invasive study to determine changes in physical properties of multilayer materials

Exposure to different types of sources, such as electrical or thermal, can cause changes in the structure of materials, for example, cracks, stresses, oxidation, corrosion, among others. The goal of this work is to be able to determine changes in the material produced by high stress and/or high temperatures. To this end, the estimation of some specific electrical and thermal properties of a multilayer material is performed. The determination of the effective permittivity of a multilayer composite material is based on its reflectance property. Regarding the effective thermal conductivity, its value can be estimated assuming certain thermal process, and imposing that the temperature at the edges of the homogeneous body coincides with that obtained for the composed material. Numerical examples of the proposed problems are included. Graphical abstract