A new fibre-bundle pull-out test to determine interface properties of a 2D-woven carbon/carbon composite

A newly developed fibre-bundle pull-out test is utilised to determine the interface parameters between fibre bundles and matrix. This test was applied to a bidirectionally layered carbon-fibre-reinforced carbon composite produced on the polymer route with the aid of 8H-satin weave prepreg. The interface between fibre and matrix and the matrix properties were varied by graphitisation (a final heat treatment) at three different temperatures. The new test method uses the superposition of external compressive stresses on the inner clamping stresses, which enables the separation of two important interface parameters, the coefficient of friction μ and the clamping stress q0. The evaluation procedure takes into account the real geometry of the pulled-out bundles.