Resistance sensing response optimization and interval loading continuity of multiwalled carbon nanotube/natural rubber composites: Experiment and simulation

Abstract To achieve long‐term and real‐time monitoring of the deformation of isolation bearings, a conductive composite with a natural rubber (NR) matrix modified by multiwalled carbon nanotubes (MWCNTs) is processed by prestrain. The resistance‐strain response of this composite indicates excellent uniformity, linearity, hysteresis, reproducibility and stability due to the prestrain process for the composite before application. To explain the mechanism of the resistance‐strain response for the composite, a theoretical model is developed to analyze the relation between the conductivity and the MWCNT network structure. Mechanical and electrical testing under cyclic loads indicates that the prestrain of the composite could reduce or even eliminate the ‘shoulder peak’ effect of the resistance‐strain curve. Meanwhile, the resistance‐strain response behavior is independent of the prestrain temperature and discontinuous before and after the interval time. Furthermore, the coarse‐grained molecular dynamics simulation and microstructure testing indicate that the resistance‐strain response is induced by the changing orientation of MWCNT molecules in the rubber matrix under tension loading. All of the results and findings provide potential applications of this MWCNT/NR composite for deformation monitoring.