Overall elastic characterization of equivalent FE models for aluminum foams through computational homogenization approach and genetic algorithm optimization

Aluminum foams are gaining increasing interest because of their widespread set of functional attributes combined with highly specific structural properties and affordable manufacturing processes. The finite element analysis of foam materials is typically performed with complex and time-consuming 3D models. Here, a beam FE model strategy is utilized to obtain a precise and time-saving simulation instrument for open-cell aluminum foams. The beam FE modeling is based on the Kelvin cell as a fundamental unit and provides a simplified geometrical description of the intersection node between ligaments whose elastic properties need to be adjusted through a calibration procedure. The beam FE model elastic properties are measured through a homogenization procedure that evaluates the elastic constants of an equivalent material. The issue of model calibration is formulated as an optimization problem exploiting the NSGA-II genetic algorithm. This procedure allows obtaining the full elastic calibration of the beam FE model, reproducing the orthotropic elastic behavior of the aluminum foams with reduced computational efforts.