Modeling the effective viscoelastic properties of PEEK matrix reinforced by arbitrary oriented short glass fibers

Abstract

The aim of this work consists in estimating and modeling the viscoelastic behavior at small strain of KetaSpire® KT-880 PEEK fiber composites reinforced with short glass fibers. The viscoelastic behavior of the PEEK matrix is identified from a series of DMA tests at different temperatures. The principle of time–temperature superposition is used to build a master curve in order to identify the parameters of a generalized 13-branch Maxwell model. The composite’s master curves are constructed by using virtual DMA experiments. These master curves are used to identify a generalized, transversely isotropic Maxwell spectral law. The modulus of each branch of the model is linked to the characteristic time of the branch by a normal distribution function (spectral law), which allows drastically reducing the number of material parameters. Finally, a metamodel is built to estimate the behavior of the composite as a function of the microstructural parameters: fiber volume fraction and fiber orientation distribution function.