Data and code for "Two-input reconstruction of the biaxial first-yield envelope of elliptically perforated auxetic sheets"

Abstract

Research data and analysis code accompanying the article Two-input reconstruction of the biaxial first-yield envelope of elliptically perforated auxetic sheets, under review. The deposit contains four things. (1) The periodic-homogenization source code and the 18-node wedge finite-element kernel that produced every effective constant reported in the article. (2) The first-yield surface code: Gauss-point stress operators, the 360-direction biaxial first-yield locus and its extrema. (3) The mesh generator, a NumPy/SciPy DistMesh implementation with exact projection of hole-edge nodes onto the true ellipse. (4) The computed effective constants and full 360-direction first-yield loci for all twenty-eight geometries on the rule-compliant meshes the article reports, and on the uniform mesh set of its sensitivity comparison, twenty calibration geometries and eight held-out off-grid geometries whose coordinates were fixed before any was analysed and which enter no fit at any stage, together with the raw compression records from the eight printed specimens, exactly as exported by the testing machine. Also included are the analysis scripts that reproduce the numbers quoted in the article and the generators for the fourteen figures the article embeds and its four supplementary figures, the mesh caches on which the analysis scripts run (the retained Gauss-point stress fields are not deposited; hotspot_run.py and d4_run.py regenerate them, see README section 0), the runs on symmetry-preserving meshes for all twenty-eight geometries, the h-refinement study at the first-yield hotspot, a SHA-256 manifest of every file and the frozen Python environment. Effective moduli are in MPa for a base material of E = 222000 MPa and Poisson ratio 0.3; yield radii are normalised by the base material yield stress and are therefore dimensionless functions of the geometry alone; lengths are in mm and angles in radians. Full schemas, units, reproduction commands and the tested Python and package versions are in README.md. Licensing is scoped: the data (everything under data/) is released under CC BY 4.0, the source code (everything under code/) under the BSD 3-Clause licence. See LICENSE and LICENSE-CODE.