Proposition of a modal filtering method to enhance heat source computation within heterogeneous thermomechanical problems

This paper presents a new approach to evaluate heat sources from thermal field measurements. A modal projection based on dynamics (Discrete Modal Decomposition) is used to estimate the spatial term of a heat diffusion problem. A numerical example is presented in order to validate this approach and compare it to a more classical spectral decomposition (based on thermal considerations). Results show that the proposed projection basis not only provides closer assessment of the heat sources but is also more stable to noise and side effects. Finally, a basis enrichment method is presented and tested. It shows that a priori knowledge of the heat sources shape though approximated (e.g. from strain measurement) enhances the assessment of calorific effects accompanying material deformation.