O. S. Bruller’s research while affiliated with Technische Universität München and other places

The response of nonlinear viscoelastic creep of neat and carbon fiber-reinforced Polyether-etherketone (PEEK) and epoxy resin at different temperature was studied using Schapery's constitutive equation. As reinforced materials, the laminates [904]s and [±454]s were investigated. For comparisons reasons, the same type of experiments was conducted on the respective neat polymers. The results show that the linear viscoelastic limit is shifted to lower values with increasing temperature. This was observed for neat polymers as well as for the [±454]s laminates. On the other hand, for the [904]s laminates, the influence of the temperature on the linear viscoelastic limit seems to be relatively restricted. Besides, for all resins and laminates studied, it is shown that the influence of temperature on the nonlinearity of the instantaneous material response is significantly lower than that on the transient nonlinearity.