The optimization of the industrial steel building

The paper presents the structural optimization of a single-storey industrial steel building. The structure is consisted from equal frames which are mutually connected with purlins and rails. All structural elements are proposed to be built up of standard hot rolled I sections. The structural optimization is performed by the Mixed-Integer Non-linear programming approach, MINLP The MINLP performs a discrete topology, material and standard dimension optimization, while continuous parameters are simultaneously calculated inside the continuous space. Since the discrete/continuous optimization problem of the steel building structure is non-convex and highly non-linear, the Modified Outer-Approximation/Equality-Relaxation (OA/ER) algorithm has been used for the optimization. Alongside the optimal structure mass, the optimal topology, structural steel grade and standard I sections have been obtained. The paper includes the theoretical basis and a practical example with the results of the optimization.