On the performance of flax fibres in multi-objective design of laminated composite plates for buckling and cost

With rising environmental concerns, the application of environmentally friendly sustainable materials for engineering designs has attracted much attention. The bio-fibres are examples of such materials, which are increasingly used as reinforcement material in composites. One of the widely used bio-fibres is flax fibre, which is a cost-effective reinforcement material with comparable mechanical properties to those provided by glass fibres. In this study, the effects of the flax fibre on the multi-objective optimum design of the hybrid laminated composite plates for maximum buckling and minimum cost under different material configurations, including graphite-flax/epoxy and graphite-glass/epoxy, are investigated. To deal with this problem, two approaches are employed. The first one converts the multi-objective problem into an equivalent single-objective one by introducing the weighting parameters for the buckling load factor and cost. While the other is the multi-objective approach in which the Pareto front solutions are obtained by considering separate objective functions. The optimum designs obtained for a 64-layer laminated composite plate under different loading conditions suggest that the application of the graphite-flax/epoxy instead of the graphite-glass/epoxy not only can reduce the costs, but also can enhance the buckling strengths.