Simulation of auxetic structures under stress by using a tensegrity bar-spring model and constraint optimization of Spring energy. This is a generalization of the material scientific analyzis of bar-joint frame works done in the project of statistical methods in algebraic geometry.
The matlab code provides the energies, constraints and scripts (RunBMNNBig, RunBMNSmall and ScriptBMN for the medium sized) for three different starting configurations and one compression (default is expansion)
the python code only provides files for the medium sized configuration (compare scriptBMN.m)