Investigating the effects of flax fibers application on multi-objective optimization of laminated composite plates for simultaneous cost minimization and frequency gap maximization

In recent years, the application of flax fiber reinforced composites has attracted much attention from the automobile and construction industries. From the composites reinforcement point of view, the flax fiber is an efficient alternative to the glass fiber in terms of the cost, mechanical properties and environmental effects. The current study investigates the multi-objective optimization of hybrid laminated composite plates with objective functions of minimizing the cost and maximizing frequency gaps. In order to assess the capabilities of the flax fibers in reinforcing composites, a set of multi-objective design optimization problems of hybrid composite plates with discrete design variables of material types and fiber orientations are investigated. Numerical results obtained from the hybrid graphite-glass/epoxy and graphite-flax/epoxy composite plates with different aspect ratios demonstrate that the application of flax fibers can not only reduce the cost and increase the fundamental frequency, but also provide the optimum designs with bigger gaps between two consecutive natural frequencies.