READ ME ======================== General information ======================== Author: Sadaf Maramizonouz, Sadegh Nadimi, William Skipper, Roger Lewis Contact: sadaf.maramizonouz@newcastle.ac.uk, sadegh.nadimi-shahraki@newcastle.ac.uk DOI: https://doi.org/10.25405/data.ncl.21710669 License: CC BY 4.0 Last updated: 24/04/2023 Related article: Characterisation of Physical and Mechanical Properties of Seven Particulate Materials proposed as Traction Enhancers ======================== Introductory information ======================== Files included in the data deposit (include a short description of what data are contained): 1) The spreadsheet entitled "Characterisation of the Particulate Materials Proposed as Traction Enhancers" contains five individual sheets, one for each of the investigated properties including density, bulk behaviour (AoR), particle size distribution, mechanical properties (Nano-Indentation), and mineralogical properties (XRD). 2) The "Shape Characterisation" folder is comprised of one *.PDF file entitled "Characterisation of Shape and Shape Descriptors of the Particulate Materials Proposed as Traction Enhancers" which includes the graphs for the shape characterisation, and ten items including British and Austrian rail sand, dolomite, waste glass beads, coated (coarse and fine) and non-coated alumina, and recycled crushed glass (three sizes). Each of these items contain more than 50 MATLAB data files corresponding to a single particle of the aforementioned material which has been scanned through µCT and includes the three-dimensional geometry of the particle along with all the particle data and characteristics. These data files are saved as “particle types” and can be loaded and read in the MATLAB interface. Additionally, the three-dimensional geometries of each single particles are included as *.STL files in the folder corresponding to each candidate material. Explain the relationship between multiple data sets, if required: N/A ========================== Methodological information ========================== A brief method description – what the data is, how and why it was collected or created, and how it was processed: This dataset provides the characteristics of particulates used as rail sand in the train’s wheel/rail interface (via an on-board system) to facilitate the train’s acceleration and deceleration. Seven materials are studied including Austrian rail sand, standard Great British rail sand, waste glass beads, recycled crushed glass, non-coated alumina, coated alumina, and dolomite. The main objective of this research is to provide a physical and mechanical characterisation of these granular materials in terms of their density, bulk behaviour, particle size, particle shape, hardness, reduced modulus and mineralogical properties. In particular, three-dimensional raw and post-processed micro-computed tomography images of more than 1200 particles are shared. The results provide a detailed dataset which can be used in ongoing and future experimental and numerical investigations studying the role of particulates in the wheel/rail interface. Instruments, hardware and software used: Particles’ density was assessed using the gas jar method following BS1377-2:1990using an end-over-end shaker. Particles’ AoR was assessed using the procedure proposed by the technical committee of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE TC105) as a part of a round robin test. Particles’ sizes were characterised by sieving. Particles’ shapes were characterised using X-ray micro-Computed Tomography (µCT) scan system (SkyScan 1176) located at the Preclinical in-Vivo Imaging Facility at Newcastle University Medical School, United Kingdom. Shape characterisation of particles and calculation of shape descriptor parameters including surface area, volume, elongation, flatness, sphericity, and convexity are performed utilising the SHAPE code by Angelidakis et al. publicly available from the link below: https://github.com/vsangelidakis/SHAPE Image analysis is performed using the open-source software Fiji-ImageJ (1.53c) and MATLAB (R2021a). Particles’ three-dimensional geometry were generated using the MATLAB function “savestl (node, elem, fname)” which is provided by the Iso2Mesh code and needs three inputs: particle vertices as node, particle faces as elem, and file name as fname. It will save the particle geometry as an *.STL file which can be used in any computer-aided design (CAD) software and numerical simulation code. Particles’ mechanical properties were assessed using a nano-indentation instrument (NanoTest Vantage) with a diamond Berkovich indenter. Particles’ mineralogical characteristics were assessed using powder X-ray diffraction (XRD) experiments utilising the diffractometer (Bruker D2 Phaser with LynxEye detector using Cu Ka radiation). Date(s) of data collection: 2021, 2022, and 2023 Geographic coverage of data: N/A Data validation (how was the data checked, proofed and cleaned): For all tests, two main points have been considered. Firstly, that the samples of each candidate material are produced in a manner to represent the whole batch. Secondly, that each test is repeated enough times to obtain reasonable data. To measure the density of the materials the British Standard (BS1377-2:1990) was followed step by step and as accurately as possible. The samples for particle shape characterisation through µCT imaging were prepared with utmost care to ensure two factors. One, that there are enough number of particles for each material candidate to warrant adequate data. Two, that there are no touching particles to achieve accurate image analysis. For this purpose, a long piece of tape was fixed to the work surface, the particle sample was lightly sprinkled on top, and the connecting particles were disconnected using a fine tip tweezer. Then, another long piece of tape was placed on top of the sprinkled sample with the sticky side down sandwiching the particles. This ensured that the particles will not move during testing. Finally, the prepared sample was rolled to form a cylinder and placed in an individual cylindrical container for imaging. The nano-indentation tests were fully compliant to all relevant international nanoindentation standards including ISO14577 (the ISO standard for instrumented indentation) and ASTM E2546–07. The samples were chosen with utmost care to provide particles with at least one flat surface. The particles were then mounted on the stub with their flat surface on top and positioned horizontally to enable accurate indentations. The results of the XRD tests were compared to the data provided by Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) (located at School of Engineering, Newcastle University, United Kingdom) to ensure their accuracy. Overview of secondary data, if used: N/A ========================= Data-specific information ========================= Definitions of names, labels, acronyms or specialist terminology uses for variables, records and their values: AoR: Angle of Repose µCT: X-ray micro-Computed Tomography XRD: powder X-ray diffraction COD: Crystallography Open Database CAD: computer-aided design SEM: Scanning Electron Microscopy EDX: Energy Dispersive X-Ray Analysis Explanation of weighting and grossing variables: N/A Outline any missing data: The available amount of two candidates, namely, Austrian rail sand, and waste glass beads, were not sufficient for for measuring their density and angle of repose.