Bending and torsion of cold-formed steel sigma and lipped-channel beams: test database, finite-element analyses and design-calibration code

This dataset contains test data, finite-element analyses and code for cold-formed steel sigma (web-stiffened) and lipped-channel beams under combined bending and torsion, used to evaluate and calibrate design rules for these members, including machine-learning corrections calibrated on finite-element databases. It contains: (A) a database of 96 bending-torsion tests from four laboratories, with section geometry, material properties, loads and the predictions of the design methods and finite-element protocols; (B) the registry of the shell finite-element analyses, one row per analysis with its model parameters; (C) the collected results of every analysis (capacity, kind of peak, increment of the peak, section rotation and failure mechanism); (D) the load paths (Abaqus status files) from which the capacities were read; (E) the Abaqus input decks; (F) the design, calibration, statistical and machine-learning code with its tests; (G) the scripts that built, ran, collected and judged the finite-element analyses; and (H) the analysis plans with their hashes, which are also registered on OSF (https://osf.io/vpkdr). A README describes every file, the naming of the analyses, and the units and sign conventions. Data are released under CC BY 4.0 and code under the MIT licence. Abaqus is commercial software and is not included. Version 1.2 (October 2026) adds the 129 finite-element analyses of the second analysis round (114 nonlinear, 7 linear-elastic and 8 eigenvalue-only) with their input decks, load paths and collected results; the later re-analyses of existing results and the calibration code, with their tests and reports; and the machine-learning studies, including 400 nonlinear analyses added by active learning and five refined re-runs of three analyses. Files of version 1.1 that did not change are carried over; some working notes and manuscript drafts of version 1.1 are not part of version 1.2. Version 1.3 (October 2026) adds analyses on stored or published data, with no new finite-element analysis: tests of the machine-learning results on a published database of cold-formed steel channels with slotted webs in shear (Degtyarev, Mendeley Data, 2020, CC BY 4.0, https://doi.org/10.17632/t9hhkngdwv.1; not redistributed here); low-data baselines with a trend or a capacity scale, screened fits of the sigma and lipped-channel database with whole cross-sections held out, and descriptive re-reads of stored results; and a check of section size against the calibrated resistance factor. It also adds the stored results of an earlier screened machine-learning analysis that these scripts read, and the scripts that write the supplementary result tables from the stored results. Files of version 1.2 are carried over; one archive is rebuilt with a reworded note. In total the record contains 3,875 non-linear shell finite-element analyses, each with its input file, its load path (Abaqus status file; two smoke runs that stopped in their first increment have none) and its collected results, and 15 further linear-elastic or eigenvalue-only analyses; 1,628 of the non-linear analyses belong to the parametric blocks of the two-family programme (run names beginning SFS_P2). The input files include the buckling analyses that seed the geometric imperfections. The Abaqus output databases and run files are not deposited because of their size; they are archived by the authors with SHA-256 manifests and are available on request.