Effects of γ-radiation on mechanical behaviour of carbon/epoxy composite materials

Mainly because of their excellent specific properties, the use of polymeric matrix composite (PMC) materials in space structures and energy applications is growing increasingly. However, when space and nuclear environments are considered, the strength of PMC materials could be adversely affected due to the exposure to different types of radiation and their effects must be assessed in order to evaluate the suitability of the composite material chosen for the application. Radiation is known to affect PMC materials both by breaking polymeric chains and by causing changes in molecular constitution due to the action of free radicals. The combination of these two effects characterizes the mechanical behaviour of the irradiated material. But it is not only the characteristics of the radiation source (type, rate, total dose, etc.) that must be considered, because the presence of other environmental factors, especially the temperature, can be added to the radiation effect, yielding an unforeseen synergistical influence on the results. In this work, the behaviour of short beam shear specimens of a carbon/epoxy material submitted to gamma-irradiation up to 10 MGy and tested at temperatures ranging from -60 to 130 degrees C is presented. (C) 1998 Elsevier Science Ltd. All rights reserved.