CREEP-BEHAVIOR OF A HYBRID FIBER (GLASS/CARBON) REINFORCED COMPOSITE AND ITS APPLICATION

An overall understanding of composite materials is needed in order that they can be applied to practical applications. A description of the creep behaviour is required when these materials are operated at elevated temperatures. This paper addresses a hybrid short-fibre-reinforced composite material which was substituted for steel in the fabrication of a valve component. The material was investigated on the basis of its intended service conditions. Creep behaviour of the material at high- and low-stress levels is presented in the form of strain/time and stress/time diagrams. A good deal of attention has been given to the extrapolation method which is shown to have an effective application for stage II creep. A creep damage parameter associated with modulus adjustment is proposed and subsequently analysed, thus providing an assessment of the composite creep behaviour. Finally, the creep mechanism is discussed along with a fractographic analysis.