Works with - python 2.7 - numpy 1.11.3 - scipy 0.19.0 This folder contains : - main.py : Call to solver, definition of input parameters. - bilevel.py : Bi-level solver procedure. - categorical.py : Categorical data : each choice corresponds to a material and a stiffener, It is possible to change / add new catalogs. - lower_pb.py : Implementation of Psi(c) function (lower level problem), Definition of constraints, objective, call to scipy continuous solver. - truss_3b : Implementation of tress and displacements computations for 3-bar truss structure, Implementation of weight computation Implementation of buckling limit stress computation (to be adapted if change of stiffener profile)