THE APPLICATION OF COMPOSITES IN AEROSPACE

After the introduction of the advanced composite materials, i.e. carbo n- and aramidfibre reinforced thermosets, in the late 60's, for a long time the application of these materials used to be considered a panac ea for many problems in civil aircraft structures. After many years of trial and error, it is becoming clear that these materials most certa inly contribute to better aircraft, but are not a miracle cure. And if there is a key role for composite materials, there is still a long wa y to go to the all composite (commercial) aircraft. The applications i n the aerospace market started with components that used to be designe d in glassfibre reinforced thermosets. Although the manufacturing tech nology was well known, the approach to designing in advanced composite s changed in the sense. that the designs had to be optimized for minim um weight (to obtain lower DOC). Also the materials had to be recogniz ed by the designer as being anisotropic (high allowable stresses in th e fibre direction). Soon it became evident that also the material- and process technology had to be optimized for the advanced composites. D ue to the cost involved in the manufacturing of highly loaded composit e components, the design philosophy changed from design for minimum we ight to (more or less) design for minimum cost. Also the service exper ience and resulting remarks from the operators. changed the design app roach. The maturity of automated manufacturing will enable further cos t reduction and after sufficient service experience with the component s that are flying at this moment, the aircraft industry will be ready for the next step: the application of the advanced composite materials in primary, flight-critical aircraft components. The close cooperatio n between the aerospace industry and the material suppliers will be an essential condition for success in the quest for a ''better'' aircraf t.