Stefanos AthanasopoulosDoctoral Student
Research areas and keywords
UKÄ subject classification
- Engineering and Technology
- Granular Mechanics, In-situ Testing, Neutron Strain Scanning, Digital Image Correlation
The general scientific field of my PhD project is Geomechanics and more specifically, the mechanics of granular geomaterials (e.g., sands), which is important in a wide range of civil engineering and infrastructure projects (e.g., foundation, tunneling, hydrocarbon exploitation, underground waste disposal, etc.). The objective of the project is to improve the understanding of the micro-mechanisms that lead to degradation and, eventually, failure of these materials during mechanical loading. With such understanding it will be possible to derive improved material models for better numerical simulations of granular media, in general.
In particular, in my research I am working on the development of a new, multiscale experimental approach for studying granular media under load, enabled by the simultaneous application of Neutron Strain Scanning (NSS) and Digital Image Correlation (DIC), using a specially designed plane-strain apparatus. NSS is a diffraction–based technique that has been successfully used to infer the force/stress distribution in polycrystalline materials under load, by measuring the variations in interplanar distances of crystals (i.e., the crystallographic – or grain – strains), whilst DIC is a technique that has been used extensively over the past few decades to derive the strain field of various materials under load. The aim of my research has been, at first, to develop an appropriate experimental set-up to achieve the envisaged combination of measurements within a single experiment and then, to quantitatively associate the traditional macroscale boundary measurements with the mesoscale DIC-derived strain field and the NSS-inferred microscale stress distribution.
Recent research outputs
Research output: Thesis › Doctoral Thesis (compilation)
Research output: Chapter in Book/Report/Conference proceeding › Book chapter
Research output: Contribution to conference › Abstract