Mini shear box tests on crushed sand fragments under high normal stresses

This data set contains measurement data of mini shear box texts conducted on rail sand under 300MPa, 600MPa and 900MPa normal stresses, which are typical stresses in railway operation.Please see the following paper for a detailed explanation:K. Six, W. Skipper, R. Lewis, B. Suhr: A DEM based approach to understand the physics in sanded wheel-rail contacts. Proceedings of the 13th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems (CM2025), Tokyo, Japan, September 22-26, 2025 https://doi.org/10.5281/zenodo.15600135 The mini shear box is circular with a diameter of 5mm. The sand tested is typically used in Great Britain for sanding wheel-rail contacts and is named GB sand here. The sand is filled in and normal stresses of 300MPa, 600MPa and 900MPa are applied, which corresponds to vertical forces of 5.89kN, 11.78kN, 17.67kN. The sand grains crush under the applied stresses and sand fragments solidify under such high stresses to a tablet like specimen of about 4mm height. The test rig in vertical direction operates force controlled. The measured vertical force, which is used by the controller, shows a dependency from the shear forces. This undesired behaviour is thought to be caused by the placement of the used strain gauges. Thus, the results presented here should be seen as indication, an error of up to 20% in the vertical force is possible.After the normal stress is applied, the shearing of the specimen starts (position controlled). The measurement data is contained in csv files and file names contain the applied stress and a number of the test, e.g. GBsand_shear_300MPa_1.csv is conducted under 300MPa and is test no 1. For each level of applied stress three measurements are conducted resulting in nine data files. Each file consists of 7 columns:column 1: vertical displacement of top plate [mm]column 2: vertical (normal) force measured on top plate [kN]column 3: vertical displacement of bottom plate [mm]column 4: vertical (normal) force measured on bottom plate [kN]column 5: shear displacement [mm]column 6: shear force [kN] Please see the referenced paper for further details on the conducted experiments. https://doi.org/10.5281/zenodo.15600135