Please cite this article as: Jäger, J., Sause, M.G.R., Burkert, F., Moosburger-Will, J., Greisel, M., Horn, S., Influence of plastic deformation on single-fiber push-out tests of carbon fiber reinforced epoxy resin, Composites: Part A (2015), doi: http://dx.
AbstractIn our study we present a procedure to measure and analyze single-fiber push-out force-displacement curves on carbon fiber reinforced polymers using a cyclic loading-unloading scheme. The measured cyclic force-displacement curves allow an energy-based evaluation of the interfacial failure, taking into account elastic, plastic and other dissipative energy contributions. Experimental and modeling results demonstrate that a deviation of the push-out curve from linear behavior does not correspond to crack opening but to a plastic deformation of the matrix. Evaluating the plastic energy yields a linear increase of the total plastic energy after a certain indenter displacement. This linear increase is attributed to stable crack propagation.Back-extrapolation of the linear part to zero total plastic energy using a linear regression yields the initiation of crack growth. It is concluded that for ductile matrix materials like polymers, a reliable interpretation of push-out data has to take into account plastic material deformation.