DOI: 10.57745/mxemi4
title: X-ray scan of soft ball compression experiments - raw data - 3D DIC data - post-processed data

description: These data are associated with the results presented in the paper: Compacting an assembly of soft balls far beyond the jammed state: insights from 3D imaging They are scans of compressed millimetric silicon balls. Micro glass beads are trapped in the silicone so that 3D DIC can be performed. Post-processed data including displacement fields, strain fields, contacts to name a few are also available. More details about the experimental protocol and data post-processing can be found in this publication. How data are sorted The raw and post-processed data of 4 experiments are available here. For each experiment: - a 'scan' folder includes 'scan_XX' folders where 'XX' corresponds to the N compression steps. Inside each of these folders you can find 8-bit png pictures corresponding to the vertical slices of the density matrix of a given compression step. Not interesting slices, because particles are not seeable have been removed for the sake of saving space. - a 'result' folder contains all the data post-processed from the density images. More specifically: - 'pressure_kpa.txt' is a N vector giving the evolution of the applied pressure (in kPa) on the loading piston, where N is number of loading steps. - 'particle_number.txt' is a n vector telling to which particle a correlation cell belongs. n is the number of correlation cells. - 'particle_size.txt' is a m vector where m is the number of particle in the system. It gives the particle size : 1 for large particles, 0 for small ones. Particle numbering corresponds with 'particle_number.txt' - Following text files are Nxn matrices where N is the number of steps and n is the number of correlations cells. They give for each correlation cell, the evolution of an observable measured in the corresponding volume of the correlation cell: - 'position_i.txt' is the position of the cell along i axis - 'position_j.txt' is the position of the cell along j axis - 'position_k.txt' is the position of the cell along k axis - 'correlation.txt' is the evolution of the correlation value when performing the 3D DIC. This constitutes the goodness of measurement of the correlation cell positions - 'dgt_Fij.txt' is the evolution of the deformation gradient tensor for each of its ij components - 'energy.txt' is the evolution of the energy density stored in the material - 'no_outlier_energy.txt' is a boolean ginving, from the energy density measurement, if the observables can be considered as an outlier (0 value) or not (1 value) - Following text files are mxN matrices with self-expicit contents where N is the number of loading steps and m the number of grains (particle numbering corresponds with 'particle_number.txt'). They give for each grain, the evolution of an observable measured at the grain scale. The major direction is the direction in which the particle is the longest. The minor direction is the direction in which the particle is the shortest. Theta and phi are the azimutal and elevation angle respectively: - 'particle_asphericity.txt' - 'particle_area.txt' - 'minor_direction_theta.txt' - 'minor_direction_phi.txt' - 'minor_direction_length.txt' - 'major_direction_theta.txt' - 'major_direction_phi.txt' - 'major_direction_length.txt' - Following text files are N vectors with self-expicit contents where N is the number of loading steps. They give the evolution of a system observable during loading. If a second vector is given it is the evolution of the standard deviation of the observable. In the case of contacts 'proximity' et for contacts obtained only from proximity criterion and 'density' is for contacts obtained from scanner density criterion. 'std' stand for standard deviation: - 'global strain.txt' measured from the system boundaries evolution - 'packing_fraction.txt' measured from the system boundaries and particle volume evolution - 'average_contact_surface_proximity.txt' - 'average_contact_surface_density.txt' - 'average_contact_radius_proximity.txt' - 'average_contact_densitt_proximity.txt' - 'average_contact_outofplane_proximity.txt' - 'average_contact_direction_proximity.txt' - 'average_contact_direction_density.txt' - 'average_contact_asphericity_proximity.txt' - 'average_contact_asphericity_density.txt' - 'average_vonMises_strain.txt' - 'std_vonMises_strain.txt' - 'average contact direction_density.txt' - 'average_energy.txt' - 'std_energy.txt' - 'contact_proximity.txt' number of contact - 'contact_density.txt' number of contact - a 'contact_density' folder includes 'XX' folders corresponing to the N compression steps. Each of these 'XX' folders includes 'ijkP_AA_BB.txt' files which gives information about potential contact points between AA and BB grains. For each potential contact, 'ijkP_AA_BB.txt' gives the i,j and k position of the potential contact points in AA and the average local density value associated which gives the probability of contact. - a 'contact_proximity' folder includes 'XX' folders corresponing to the N compression steps. Each of these 'XX' folders includes 'ijkD_AA_BB.txt' files which gives information about potential contact between AA and BB grains. For each potential contact, 'ijkD_AA_BB.txt' gives the i,j and k position of the potential contact points in AA and the shortest distance between this point and grain BB boundary. - a 'grain_mesh' folder includes 'XX' folders corresponing to the N compression steps. Each of these 'XX' folders includes 'YY.stl' files each of them is the mesh of the borders of the YY particle of the packing. - a 'contact_mesh' folder includes 'XX' folders corresponing to the N compression steps. Each of these 'XX' folders includes 'AA_BB.stl' files each of them is the mesh of the contact between particle AA and BB.