Multi-phase ELAStic Aggregates (MELASA) software tool for modeling anisotropic elastic properties of lamellar composites
|Year of publication
|Article in Periodical
|Magazine / Source
|Computer Physics Communications
|MU Faculty or unit
|composites; elasticity; anisotropy; superlattices; coherency; web application
|We introduce a new web-based tool called MELASA (Multi-phase ELASticAggregates), open-access available at https://melasa.cerit-sc.cz, for computations andvisualizations of anisotropic elastic properties of lamellar (nano-)composites. MELASAimplements a linear-elasticity method by M. Grimsditch and F. Nizzoli (Phys. Rev. B 33(1986) 5891), originally developed for superlattices of any symmetry. Our toolcomputes anisotropic elastic properties of a specific type of periodically reperatedlamellar (nano-)composites using matrices of elastic stiffnesses of co-existing phasesas input. Elastic properties are visualized in the form of directional dependencies ofselected elastic characteristics (Young's modulus and linear compressibility). MELASAfurther generalizes the Grimsditch-Nizzoli approach, which was originally formulated foronly two phases, to multiple-phase composites. Additionally, our implementation allowsfor treating internal rotations of local coordination systems corresponding to the naturalset of coordinates that match directional vectors of unit cell defining crystal latticewithin the co-existing phases. Fe-Al-based superalloy nanocomposites are employedas a numerical example of superlattices with the input and output elastic stiffnessesdetermined by quantum-mechanical calculations. In particular, three different atomicconfigurations of interfaces in superlattices containing the ordered Fe3Al phase and adisordered Fe-Al phase with 18.75at.\%Al (modeled by a special quasi-randomstructure, SQS) are considered. They differ by relative positions of sublattices in Fe3Al(an antiphase-like shift) and/or atomic planes in Fe-18.75at.%Al with respect to theinterface.