Data and code for size-dependent flexural band gaps and fixed-area shape design of periodic composite microplates

Supporting data and research code for the manuscript “Size-dependent flexural band gaps and fixed-area shape design of periodic composite microplates” by Xin Chen, Alex Kalamkarov, and Abdolhamid Akbarzadeh. The study combines modified couple stress theory (MCST), Reddy third-order shear deformation theory, and inverse-factorized plane wave expansion for periodic steel–epoxy microplates. It includes fixed-area inclusion-boundary optimization and selected comparisons with three-dimensional solid calculations. Supplementary_Data_v19.zip contains the Data 1–8 collection mapped in the manuscript Supplementary Information: spectra, interface coordinates, optimization histories, modal-energy data, numerical checks, and model-generation/postprocessing scripts. Folder numbering and original provenance files are retained. The five-length-scale design study is exploratory; optimization protocols and discretization orders differ between runs as documented in the accompanying files. github_commit_6d51e70.zip preserves the public repository at commit 6d51e70f72e879ba2c13a3dcf06588396fe9e1bf, including research source code and selected historical supporting numerical results. It complements the newer supplementary collection and should not be interpreted as a complete input tree for every historical workflow. CSV files are readable with standard data tools and NPZ files with NumPy. Research workflows use Python and numerical libraries; three-dimensional model-generation scripts require a separately licensed COMSOL installation. Original scans used COMSOL 6.0.0.318; later design validations used COMSOL 6.2.0.290. Commercial software, licence files, and saved .mph checkpoints are not distributed. The README explains archive coverage and dependencies, and SHA256SUMS.txt provides file-integrity checks. On authorized publication, original data and documentation are licensed under CC BY 4.0 and original Python/Java source code under MIT, as specified in README_ARCHIVE.txt.