ABSTRACT
Advanced polymer composites using carbon, boron and aramid fibres first became available, albeit only in development quantities, some 30 years ago. Immediately their potential for aerospace applications was appreciated [1], but it is only over the past 10 years or so that appreciable quantities have been incorporated into production airframes. During the intervening period world production of reinforcing fibres has increased, the properties of the fibres have been improved and the price of fibres has fallen dramatically. Over the same period the requirements for aerospace materials for both military and civil applications have shifted from being performance driven to being cost-effectiveness driven, and materials must be evaluated for their impact on both acquisition and life-cycle costs. It is notoriously difficult to estimate materials and manufacturing costs accurately, and to make meaningful comparisons between competing systems. This problem is addressed by the introduction of a cost-performance index [2]. This provides a means for numerical comparison based on an assigned value for performance enhancement. Whilst it does not purport to provide a full assessment it may prove useful for preliminary design and trade studies.
