Optimal laminate sequence of non-prismatic thin-walled composite spatial members of generic section

A problem formulation and a solution methodology for minimum weight design of laminated non-prismatic thin-walled composite spatial members of generic section is presented. Optimal design is carried out subjected to deflection, buckling and frequency constraints. The values of the constraints are determined using the finite element method developed in another paper [Rajasekaran, Equations for tapered thin-walled hybrid composite spatial members of generic section. Solids and Structures, submitted for publication]. The different search and optimization algorithm, known as evolution strategies (ES) has been applied to find the optimal fibre orientation of composite laminates. A multi-level optimization approach is also implemented by narrowing down the size of search space for individual design variables in each successive level of optimization process. The numerical results presented demonstrate the computational advantage of the proposed method “evolution strategies” which become pronounced to solve optimization of non-prismatic thin-walled spatial members of generic section.