Functionalised Conductive Elastomers for Strain Monitoring of Seismic Isolation Bearings: Experiments and Molecular Simulations
Abstract
Conductive elastomers, commonly used in flexible electronics, enable real-time monitoring of deformation through changes in output resistance in response to signal variations. However, conductive elastomers often exhibit a shoulder peak effect in their output resistance response, which significantly compromises the stability of monitoring and limits their practical application. In this study, the cross-linked structure of elastomeric silicone rubber (VMQ) was modified using C-glue (VPS), and polyvinyl pyrrolidone (PVP)-functionalized multi-walled carbon nanotubes (MWCNT) were incorporated as conductive fillers (MP) to generate electrostatic repulsion and enhance dispersion within the matrix, forming a functionalized conductive elastomer. The results showed that the hysteresis area in the resistance response signal of the functionalized elastomer was reduced by 88.72%, effectively eliminating the shoulder peak effect. The mechanism behind the formation and removal of the shoulder peak effect was elucidated through a combination of experimental analysis and molecular dynamics simulations. The tensile strength and elongation at break of the functionalized conductive elastomer were increased by 69.44% and 50.91%, respectively, which endowed it with excellent strain-sensing properties, including a deformation sensitivity (GF = 16.92) and a response time of 262 ms. This elastomer was successfully applied for strain monitoring of seismic isolation bearings, with no shoulder peak effect observed during the process. It was capable of detecting residual deformation during bi-directional shear loading, providing a more accurate assessment of cumulative damage and performance degradation within the seismic isolation bearings. This novel functionalized conductive elastomer demonstrates significant potential for structural health monitoring in large-scale components.