To investigate the time-and temperature dependences of the mechanical behaviors in the transversal direction of fibers in CFRP (carbon fiber unidirectionally-reinforced plastics), three point bending experiments were conducted at various temperatures for CFRP and epoxy resin which was used as the matrix of CFRP.
The results obtained are summarized as follows:
(1) Both the CFRP and the matrix have characteristic creep compliances dependent upon time and temperature; that is, they show so-called viscoelastic behaviors.
(2) The master curve of their creep compliances can be constructed, using their thermo-rheologically simple properties. As for the time and temperature shift factors, they are entirely identical, from the quantitative point of view.
(3) The relation between the creep compliances of the matrix and the CFRP is uniquely determined by several factors such as the volume fraction of fibers, but independent of time and temperature. The relation is in good agreement with that given by the approximate averaging method which is one of the mixture laws.
