Environmental, Social, and Corporate Governance. From Unascertainable Statements to Action Plan

Companies employ Environmental, Social, and Corporate Governance (ESG) reports to inform stakeholders on their activities and achievements regarding reducing carbon dioxide emissions and lowering electricity consumption. Whereas some frameworks for ESG reporting have been standardized, the capability to independently trace real actions undertaken leaves a lot to be desired. Despite the steady evolution of IT-powered analytics, the reliability of environmentally-targeted activity is still under threat due to the inability of translating publicity-targeted efforts into quantifiable measures. This short paper constitutes an attempt to lay foundations for backing up pro-ecological ESG statements with a realistic and validated action plan. To achieve this, a 3-cycled Participatory Action Research effort is being undertaken jointly with the staff of a Central European insurance group headquartered in Poland, EU. The paper outlines the research gap, the specific research design of the ongoing empirical study as well as the expected outcomes of the research endeavor

Microyielding of Core-Shell Crystal Dendrites in a Bulk-metallic-glass Matrix Composite

In-situ synchrotron x-ray experiments have been used to follow the evolution of the diffraction peaks for crystalline dendrites embedded in a bulk metallic glass matrix subjected to a compressive loading-unloading cycle. We observe irreversible diffraction-peak splitting even though the load does not go beyond half of the bulk yield strength. The chemical analysis coupled with the transmission electron microscopy mapping suggests that the observed peak splitting originates from the chemical heterogeneity between the core (major peak) and the stiffer shell (minor peak) of the dendrites. A molecular dynamics model has been developed to compare the hkl-dependent microyielding of the bulk metallic-glass matrix composite. The complementary diffraction measurements and the simulation results suggest that the interface, as Maxwell damper, between the amorphous matrix and the (211) crystalline planes relax under prolonged load that causes a delay in the reload curve which ultimately catches up with the original path

Multi-scale modelling of compressive behaviour of materials with pronounced internal microstructure

Aviation and aerospace structural components made of composite laminates due to their internal structure and manufacturing methods contain a number of inter- and intracomponent defects, which size, dispersion and interaction alter significantly the critical compression strain level. While there are a plethora of theoretical and experimental work on the problems stability loss and fracture of composites with internal defects in the scope of classic problems of fracture mechanics, there are few theoretical and numerical analyses available for the nonclassical problems of fracture mechanics of composites compressed along layers with interface cracks. These analyses usually have been considered the simplest problems, where the composite material with pronounced microstructure and interface defects (cracks, delaminations) have been analysed as two-dimensional (2-D) continuum in the condition of plane strain state. In the scope of these analyses only parallel defects have been considered, allowing for the interpenetration of the stress-free crack faces, or assuming so-called interfacial cracks with connected edges. This thesis broadens knowledge in the area of non-classical problems of fracture mechanics. It investigates the effect of interfacial cracks interaction on the critical buckling strain in layered and fibrous composite materials under compressive static loading. The behaviour of composite is analysed on several length-scales, starting from a ply and laminate levels (in 2-D approximation), down to a single-fibre level (a full 3-D model). The statements of the problems are based on the model of piecewise-homogeneous medium model, the most accurate within the framework of the mechanics of deformable bodies as applied to composite materials with pronounced microstructure. All composite constituents are modelled as linear-elastic material, where both isotropic and anisotropic materials are considered depending on the length-scale. It is assumed that the moment of stability loss in the microstructure of materials is treated as the onset of the fracture process. Besides that, the critical strain that corresponds to loss of stability in the microstructure of the composite, either surface or internal instability, must be smaller than the critical strain that corresponds to loss of stability of the entire composite. This project involves parameterised variables, such as the crack size, the crack spacing, the layer volume fraction and the fibre volume fraction. At each length-scale two types of cracks are analysed, namely, cracks with stress-free crack faces and cracks with frictionless Hertzian contact of the crack faces. A number of finite-element models for each length-scale are developed, and are validated analytically and numerically. The models' ability to simulate practical composite structures to a useful degree of accuracy with suitable material properties is discussed. A number of parameters, which quantifies the interfacial crack interaction and crack faces contact interaction phenomena, are introduced and discussed. Qualitative discussion on the crack faces contact zones, post-critical behaviour of composites and crack propagation are presented and discussed. Finally, the subject areas for the future work are outlined.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Correlative Tomography for micro- and nano- scale defects reduction analysis in Additive Manufactured healable aluminium alloy

Designing self-healing metals is challenging because it requires high temperature conditions which can trigger the diffusion and/or local melting process of the healing agent. Proper understanding of the healing mechanism, followed by the healing treatment optimisation depends on a successful microstructural analysis performed at the exact location of a damage. Therefore, a multiresolution and multimodal imaging approach with a spatial resolution from micro- to nano- scale is required to evidence the microstructure healing efficiency