AC electrical properties as a sensor of the microstructural evolution in nanocomposite materials:: experiment and simulation

This work deals with the AC electrical properties measurements under large strain of composites strongly contrasted in the viewpoint of their electrical and mechanical properties. First, the possibility to model a strongly heterogeneous material (from the viewpoint of electrical properties) using an improvement of a RC-type model is explored; this model relates the R and C values to the geometrical characteristics of the network of reinforcing fibres. Secondly, a powerful method is developed to characterize the filler rearrangement by measuring the electrical properties. It is concluded that the evolution of the real part of the conductivity is related to the 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.