Proposing innovative technological products often requires recourse to simulation approaches in order to boost our capacity to evaluate original concepts. This is particularly true in the field of mechanics of materials, where one of the key challenges is to understand and exploit the relationship between a material’s microstructure and its usage properties.
Research on this theme was initiated by IFPEN concerning the mechanical behavior of lamellar porous materials, such as some catalyst supports (and some polymers). The objective is to have a calculation tool ultimately making it possible to dimension and develop such materials, structured on several scales (from a nanometer to a tenth of a millimeter) and capable of withstanding mechanical stresses.
The approach was based on current structural calculation capacities, which were adapted to the calculation of microstructures with lamellar or granular stacking(1). A multi-scale workflow was established based on two tools: IFPEN’s plug im!a platform for microstructure generation, and the AbaqusTM commercial calculation code, capable of effectively dealing with non-linear mechanical behavior for large systems. The atomic scale properties forming the basis for the model were themselves estimated using molecular dynamics calculations.
A sequence of numerical methods enables the various scales of the material’s structure to be crossed. This In Silicob approach was validated for the prediction of the linear behavior (elastic properties) of alumina supports.
Research is now focusing on plasticity and fracture, which governs the characteristics of interest concerning these materials in service. Within this context, a new milestone was recently reached for plasticity simulation using the finite element method, thanks to the improvement of local meshing methods. The next step will be to introduce cohesion/fracture properties in the form of a local cohesive zone-based approachc, coupled with molecular modeling techniques.
a - https://www.plugim.fr/
b - Using complex computer-based calculations.
c - Method based on the mechanics of fracture by cracking and damage mechanics.
(1) V. Le Corre, N. Brusselle-Dupend, M. Moreaud, Numerical modeling of the effective ductile damage of macroporous alumina, Mechanics of Materials 114 (2017) 161–171. DOI: 10.1016/j.mechmat.2017.08.002