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Code and data for the paper: Geometric charges and nonlinear elasticity of two dimensional elastic metamaterials

Authors: Yohai Bar-Sinai, Gabriele Librandi, Katia Bertoldi, Michael Moshe

Contact: Yohai Bar-Sinai, ybarsinai@gmail.com

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The repository contains 4 python files and one Mathematica notebook:

1. pycharge.py: The main module. Performs calculations such as the interaction matrices, linear response deformation, Young's modulus, critical strain at instability, unstable modes, etc.
2. charge_fields.py: An auxiliary module that calculates the elastic fields generated by elastic charges.
3. meshplots.py: A module to draw nice figures of the metamaterial. See README.ipynb how to recreate Figures 4,5 from the manuscript.
4. utils.py: A module with some auxiliary functions
5. Nonlinear Geometric Charges and ISF.nb: A Mathematica notebook containing analytic calculations of the Incompatible Stress Function (ISF) and the stress fields generated by elastic charges.

Instructions on how to use the python code are either in the Jupyter notebook README.ipynb, or in inline documentation. Please fell free to contact the authors with any question.