The design of fibrous composites having improved mechanical properties

Abstract
Present-day fibrous composites have very attractive longitudinal strength and stiffness characteristics, but their mechanical properties measured in other directions are much less attractive. Besides the problem of anisotropy there is a conflict in the requirements of the properties of the interface since for maximum interlaminar shear and transverse tensile strengths a strong fibre matrix bond is required while for toughness and high values of work of fracture a weak fibre matrix bond is required. This problem is discussed and more complex composites containing two component fibres are considered. This approach enables an extra set of interfaces to be introduced as a means of maximizing composite performance over a range of failure modes.