Representative elementary volume

About: Representative elementary volume is a research topic. Over the lifetime, 4105 publications have been published within this topic receiving 86863 citations.

Finite element analysis of mechanical properties of 3D five-directional braided composites

Abstract: As for 3D five-directional rectangular braided composites, a three-dimensional (3D) finite element model (FEM) based on a representative volume element (RVE) is established under the periodical displacement boundary conditions, which truly simulates the spatial configuration of the braiding yarns and the axial yarns. The software ABAQUS is adopted to study the mechanical properties and the meso-scale mechanical response of the composites. The effects of the braiding angle and the fiber-volume fraction on the engineering elastic constants are investigated in detail. The predicted effective elastic properties are in good agreement with the available experimental data, demonstrating the applicability of the FEM in the case of tension in the primary loading direction z. By analyzing the stress distribution and deformation of the model, it is proved that the RVE-based FEM can successfully predict the meso-scale mechanical response of 3D five-directional braided composites containing periodical structures.

Prediction of the large-strain mechanical response of heterogeneous polymer systems : local and global deformation behaviour of a representative volume element of voided polycarbonate

Abstract: The mechanical behaviour of voided polycarbonate has been predicted by using a detailed finite element model of the microstructure and an accurate elasto–viscoplastic model for the glassy polymeric matrix material. On the microstructural level a spatially periodic plane strain matrix with irregularly distributed voids has been considered. The voids represent low-modulus non-adhering rubbery particles under negative pressure. The constitutive model for the homogeneous parts of the material reflects the typical yield and post-yield behaviour of glassy polymers: strain rate and history dependent yield, intrinsic strain softening and subsequent strain hardening. The finite element simulations show that the irregular void distribution causes a radical change in deformation behaviour. In particular the macroscopic strain softening disappears. This transformation in macroscopic behaviour originates from the arbitrary order in which local shear bands between the randomly distributed voids are formed and subsequently harden. In the averaged overall mechanical response the individual unstable yield and post-yield behaviour of the local shear bands is evened out, resulting in an overall stable macroscopic deformation behaviour. This mechanism is believed to be primarily responsible for the toughness enhancement of heterogeneous polymer systems through the addition of easily cavitating rubbery particles.