Nodular cast iron is a Fe-C-Si metallic alloy whose microstructure consists of a matrix, composed in general of ferrite and pearlite, with graphite nodules embedded in it. Owing to its microscopical heterogeneity, the material response is governed by the properties, morphology and typology of the phases involved. This work reports on the evaluation of the elastic properties, i.e., Youngs modulus and Poissons ratio, of an equivalent homogeneous material that characterizes the macroscopic response of a nodular cast iron. Asymptotic homogenization is used to this end. This approach is applied to both 3D and 2D multiparticle cells simulated via the finite element method. Two different physically and geometrically-based criteria are considered to estimate the representative volume element (RVE), where the size of the RVE is found to be sensitive to the chosen criterion. The main microstructural features are obtained from a computational simulation of the solidification process of the material. The numerical predictions computed for the 3D and 2D cases are compared and discussed in terms of the resulting elastic properties. It is observed that the models employing 3D multiparticle cells require lower RVE sizes than the corresponding 2D models, where the latter present a stiffer elastic response.
Abstract
Nodular cast iron is a Fe-C-Si metallic alloy whose microstructure consists of a matrix, composed in general of ferrite and pearlite, with graphite nodules embedded in it. Owing to its microscopical heterogeneity, the material response is governed by the properties, morphology [...]
To contribute to the Sustainable Development Goals 2030 (SDG), optimize and meet current industrial requirements, it is necessary to simplify the design and manufacture of composite materials, achieving reduction in thickness. Traditionally, quad, symmetrical laminates have been used, with a minimum of 8 layers based on angles 0,90, ±45. However, they are not transversely homogeneous as their properties change as the thickness varies. S.W.Tsai proposes a laminate built by r repetitions of identical sub-laminates of 4 layers of angles [±Φ/±ψ], which vary continuously, called Double-Double (DD). In this way, the laminates are homogeneous, scalable and the properties are constant regardless of thickness. It is easier and faster to fabricate, more adaptable through elimination of a single layer (top or bottom), and easier merging or transition with different sub-laminates in adjacent bays. The design is carried out by means of a dimensionless formulation based on DD parameters. Applying homogenization criteria, the design spaces are established from r repetitions of sub-laminates [±Φ/±ψ], A formulation for hybrid materials is developed, for DD with two materials, where the search for synergistic effects is analyzed.
Abstract
To contribute to the Sustainable Development Goals 2030 (SDG), optimize and meet current industrial requirements, it is necessary to simplify the design and manufacture of composite materials, achieving reduction [...]