Electrically conductive polymer nanocomposites as deformation sensors

This work is related to in situ measurements of the a.c. electrical properties under large strain of composites strongly contrasted in relation to their electrical and mechanical properties. First, a RC type model has been developed to model the electrical properties of strongly heterogeneous material by the use of an improvement in the R and C models developed in the literature. The value for each resistance and capacitor is directly derived from the local characteristics of a composite simulated with a random distribution of the fillers. Secondly, a method has been used to characterize the filler rearrangement by measuring the a.c. electrical properties as a probe. It is concluded that the variation of the real part of the conductivity is related to damage of the percolating network, whereas the imaginary part of the conductivity reflects the global rearrangement of the filler in the matrix under large strain. Thirdly an attempt has been made to correlate the simulation and experimental results when damage occurs in the material.