Size Optimisation of 2D Frame Structures using Inexact Restoration

In this paper, we focus on the size optimization of frame structures with the aim of minimizing the structural weight under the necessary conditions for serviceability and usability, such as deformation and stress constraints.Using the Finite Element Method, this approach leads to the area of nonlinear programming with a nonlinear cost function as well as nonlinear inequality constraints.We tackle this issue using Inexact Restoration (IR).Unlike traditional optimization methods, the IR algorithm separates the feasibility restoration from the objective function improvement, allowing for a more efficient search for the optimal solution.This method is particularly advantageous in dealing with the complex, non-linear behavior of beam structures with various constraints.We review the theory, present our implementation and compare results using a benchmark.