Mechanical properties of bread crumbs from tomography based Finite Element simulations

Finite Element analyses of cellular cereal products were performed in order to link microstructure and mechanical properties. Different samples of model breads were elaborated by modifying the composition in order to generate different microstructures. Their final 3D cellular structure was investigated by X-ray tomography to provide an accurate description of microstructural characteristics. Moreover, an in-situ study of the fermentation step was performed to assess the bubble structure development in the dough. Two different approaches of modelling were explored in order to take into account accurately microstructural features: 3D finite cubic element mesh based on a direct transcription of the voxel image and a tetrahedral mesh. The predicted Young's modulus values were found in good agreement with experimental ones. Mechanical modelling of the fermentation step was then performed with tetrahedral meshes. At the end of the fermentation, when products have reached a relative density of about 0.3, the mechanical properties differ, allowing discriminating the different microstructures.