Finite Element Analysis on the Unloading Elastic Modulus of Aluminum Foams by Unit-cell Model
This paper presents finite element analyses (FEA) on the unloading elastic moduli of aluminum foams under uniaxial loading and bending conditions. The unit-cell model of Gibson and Ashby was utilized in the FEA with elasto-perfectly plastic material. Compression, tension, and bending tests simulations were carried out using Abaqus software. The non-linearity effect caused by structural imperfection/buckling of unit-cell was incorporated. From the compressive test simulation, it was confirmed that the results showed good agreement with the referred experimental data. This means that the developed FE model can be regarded as an RVE model of aluminum foams. Then, the deformation characteristic and elastic modulus obtained from all simulations were compared and examined. As the results, the elastic modulus obtained from bending test demonstrated higher value than that of under uniaxial loads. This discrepancy increases gradually as the relative density decreases. The mechanism responsible for generating the discrepancy in stiffness was discussed. Furthermore, this work points out the necessity of measuring both Young’s and flexural moduli for designing an engineering structure using foam materials especially when accuracy and precision are demanded.
Finite element analysis of Miura origami column under uniaxial compressive load
This paper presents the finite element analysis (FEA) of 3D printed Miura origami column under uniaxial compressive loading condition. The finite element model (FEM) was developed under elastic-perfectly plastic material model. Investigation on the yield strength and compressive modulus with two varied parameters, i.e. angle and thickness of the Miura origami column was conducted. Abaqus 6.14 software was used to conduct the simulation of compression test. The simulation result is then compared with and examined to the referred experimental data. From the simulation, it was revealed that the results from FEA of Miura-ori column with θ = 90° and t = 2 mm showed good agreement with the referred experimental data. However, FEA results mostly overestimates the mechanical properties. This discrepancy could be due to the existence of imperfections and anisotropic material of 3D printed structures.
Indentation of composite sandwich beams
Abstract Indentation of a sandwich beam is analysed as linear elastic bending of the top skin on a rigid-perfectly plastic foundation (the core). The theoretical predictions of fracture load from this simple theory are shown to be in good agreement with experimental results from indentation tests on strips of sandwich panel, with glass-fibre-reinforced plastic skins and foam core, supported on a rigid base.