On the Numerical Modelling of Conductive CNT-Polymers: The Electro-mechanical Response

In the automotive field, piezo-resistive strain sensors have been increasingly integrated into “intelligent tyres”, to monitor the operating parameters, and to transmit them in real-time to the ECU. This work deals with polymer based piezo-resistive strain sensors with Carbon NanoTubes (CNT) embedded. CNTs slightly increase the mechanical strength of the sensor while improve the conductive and piezo-resistive behaviour of the polymer. A numerical methodology based on the Representative Volume Element (RVE) is proposed to predict the mechanical and electrical response of CNT-polymer. Finite Element method has been applied to obtain equivalent properties, which have been compared to experimental data available in the literature. Good estimate of the mechanical (i.e. Young’s Modulus) and electrical (i.e., resistivity) parameters has been achieved. The proposed methodology is thus suitable to identify electrical and mechanical properties of polymers with dispersed nanofibres