Fibre reinforced hybrid composites is made by reinforcing a matrix with two or more types of fibres. For layered composite materials, it is shown from previous research that the flexural strength can be improved by hybridising carbon and glass fibres. The strain-to-failure is improved by including higher strain-to-failure glass fibre plies. The existence of hybrid effect can be potentially useful for achieving a balanced cost and weight optimal composite material.

The flexural properties of hybrid composites are affected by many parameters including fibre volume fraction, orientation of fibre, and degree of hybridisation or hybrid ratio. Finding the optimal configuration given the required flexural strength and/or flexural stiffness is not a trivial task. Traditional optimisation methods are usually based on non-dominated sorting GA-II (NSGA-II), and are very time-consuming so infeasible for practical applications.

In this paper, an optimisation method based on Design of Experiments (DoE) is presented. A factorial design is constructed and the response surfaces for the flexural strength and stiffness are obtained. The optimal design can be conveniently derived using these response surfaces.