ABSTRACT
An accelerated test programme can, however, be undertaken to build kinetic models that describe the changes over time of the behaviour of the material; these models are then used to predict the durability from a conventional lifetime criterion. Designing with composites is an interactive process between the designer and the production engineer responsible for the manufacturing technique. It is essential that a design methodology is selected and rigorously used, because many different composite materials are on the market and they can be affected by the quality of their manufacture and the environment into which they are placed. The choice of design factors of safety is an important aspect of the work; these are likely to be given in the relevant code of practice. The ageing of a polymer can be defined as a slow and irreversible variation of the material structure, morphology and/or composition, leading to a deleterious change.
