A multiobjective optimization framework for strength and stress concentration in variable axial composite shells : a metaheuristic approach

Abstract

A metaheuristic approach for variable axial composites considering multiobjective optimization is investigated. The proposed methodology is based on the combination of three main parts: a methodology for defining the orientation of the fibers in the laminate, a structural analysis program (based on the Finite Element Method) and an optimization algorithm. It is important to highlight that a radial basis function (RBF), which describes a smooth fiber pattern, is generated using control points. The novelties of the present methodology consist of a proposal for a generalized parameterization technique, which allows the investigation of mechanical strength and stress concentration of variable axial composites. Thus, NSGA-II multiobjective genetic algorithm is used as optimization tool to define the fiber orientations. Besides, ax metaheuristic approach is used in situations when it is desirable to simultaneously minimize the stress concentration factor (𝐾𝐾𝑡𝑡) and a failure criterion index (𝐹𝐹𝐹𝐹 or Φ). Two case studies are investigated: a double notched plate and a tube with a transverse hole.