Hygrothermal characteristics of carbon fibre reinforced plastics

The investigations of the moisture absorption characteristics of specimens prepared from a unidirectionally reinforced sheet of carbon fibre reinforced plastic (CFRP), Fibredux 914C, which were subjected to a variety of environmental conditions are described. Experiments were undertaken over the approx. temp. range --70-+180 deg C, employing specimens containing moisture at levels between approx 0-2 wt.%. A scheme has been developed to assess the fractional length changes which might be anticipated in specimens containing different moisture contents resulting from a change of temp., assuming no loss of moisture during the temp. change. Application of the analytical scheme to the experimental data has revealed the detailed dependence of specimen dimensions upon moisture content and temp. The investigation has served to underline the importance of knowing the humidity of the environment in which a CFRP component has to operate, and its temp., that it might be possible to predict its subsequent dimensional behaviour. 18 ref.--AA