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.

Computational micro-macro material testing

Abstract: A key to the success of many modern structural components is the tailored behavior of the material. A relatively inexpensive way to obtain macroscopically desired responses is to enhance a base matrix properties by the addition of microscopic matter, i.e. to manipulate the microstructure. Accordingly, in many modern engineering designs, materials with highly complex microstructures are now in use. The macroscopic characteristics of modified base materials are the aggregate response of an assemblage of different “pure” components, for example several particles or fibers suspended in a binding matrix material (Figure 1.1). In the construction of such materials, the basic philosophy is to select material combinations to produce aggregate responses possessing desirable properties from each component. For example, in structural engineering applications, the classical choice is a harder particulate phase that serves as a stiffening agent for the base matrix material. Such inhomogeneities are encountered in metal matrix composites, concrete, etc. A variety of materials are characterized by particulate inhomogeneities as shown in Figures 1.2 and 1.3.

Effect of sampling volume on the measurement of soil physical properties: simulation with x-ray tomography data

Abstract: The dependence of macroscopic soil parameters on sampling volume is currently the object of renewed research focus. In this paper, x-ray computed tomography data related to cores obtained in two different locations in a field soil are used to simulate this dependence. Several integration methods are adopted, to mimic different measuring devices. Calculation results, relative to the volumetric water content, volumetric air content, gravimetric water content and dry bulk density, demonstrate that the size (up to 60×60×30 mm3), shape and positioning of sampling volumes influence significantly the measured values of soil parameters. In some cases, the instrumental dependence disappears within a range of sampling volumes, in agreement with a hypothesis underlying the so-called representative elementary volume concept. However, some parameters, like the soil bulk density, do not level off with increasing sampling volumes. These observations open new avenues for research on measurement processes in soils and other heterogeneous media.

A coupled two-scale computational scheme for the failure of periodic quasi-brittle thin planar shells and its application to masonry

Abstract: A coupled two-scale framework is presented for the failure of periodic masonry shell structures, in which membrane-flexural couplings appear. The failure behaviour of textured heterogeneous materials such as masonry is strongly influenced by their mesostructure. Their periodicity and the quasi-brittle nature of their constituents result in complex behaviours such as damage-induced anisotropy properties with localisation of damage, which are difficult to model by means of macroscopic closed-form constitutive laws. The multi-scale computational strategies aim at solving this issue by deducing a homogenised response at the structural scale from a representative volume element (RVE), based on constituents properties and averaging theorems. The constituents inside the RVE may be modelled using any closed-form formulation, depending on the physics to represent. Scale transitions for homogenisation towards a Kirchhoff-Love shell behaviour were recently proposed. The microstructure is represented by a unit cell on which a strain-periodic displacement field is imposed. The localisation of damage at the structural scale is represented by means of embedded strong discontinuities incorporated in the shell description. Based on an assumption of single period failure, the behaviour of these discontinuities is extracted from further damaging RVEs, denoted as localising volume elements (LVEs). An acoustic tensor-based criterion adapted to shell kinematics is used to detect the structural-scale failure and find its orientation. For the material behaviour of the coarse-scale discontinuities, an enhanced upscaling procedure based on an approximate energy consistency has been proposed recently for the in-plane case and is extended to the out-of-plane case. Such a multi-scale scheme can be implemented using parallel computation tools. The corresponding multi-scale simulation results are compared to direct fine-scale computations used as a reference for the case of masonry, showing a good agreement in terms of load bearing capacity, of failure mechanisms and of associated energy dissipation.

Identifying Structure–Property Relationships Through DREAM.3D Representative Volume Elements and DAMASK Crystal Plasticity Simulations: An Integrated Computational Materials Engineering Approach

Abstract: Predicting, understanding, and controlling the mechanical behavior is the most important task when designing structural materials. Modern alloy systems—in which multiple deformation mechanisms, phases, and defects are introduced to overcome the inverse strength–ductility relationship—give raise to multiple possibilities for modifying the deformation behavior, rendering traditional, exclusively experimentally-based alloy development workflows inappropriate. For fast and efficient alloy design, it is therefore desirable to predict the mechanical performance of candidate alloys by simulation studies to replace time- and resource-consuming mechanical tests. Simulation tools suitable for this task need to correctly predict the mechanical behavior in dependence of alloy composition, microstructure, texture, phase fractions, and processing history. Here, an integrated computational materials engineering approach based on the open source software packages DREAM.3D and DAMASK (Dusseldorf Advanced Materials Simulation Kit) that enables such virtual material development is presented. More specific, our approach consists of the following three steps: (1) acquire statistical quantities that describe a microstructure, (2) build a representative volume element based on these quantities employing DREAM.3D, and (3) evaluate the representative volume using a predictive crystal plasticity material model provided by DAMASK. Exemplarily, these steps are here conducted for a high-manganese steel.