Novel nanocomposite technologies for dynamic monitoring of structures: a comparison between cement-based embeddable and soft elastomeric surface sensors

TLDR

The authors present two cost‑effective nanocomposite strain sensors—one cement‑based resistor for embedding in concrete and one elastomeric capacitor skin for external deployment—each employing distinct physical principles. This study evaluates the potential of both sensors for dynamic monitoring of civil structures. The sensors were dynamically characterized on a uniaxial test machine and then tested on a full‑scale concrete beam, with performance compared to off‑the‑shelf accelerometers. Results show both nanocomposite sensors match mature accelerometers in vibration‑based structural health monitoring, indicating their promise for large‑scale structural systems.

Abstract

The authors have recently developed two novel solutions for strain sensing using nanocomposite materials. While they both aim at providing cost-effective solutions for the monitoring of local information on large-scale structures, the technologies are different in their applications and physical principles. One sensor is made of a cementitious material, which could make it suitable for embedding within the core of concrete structures prior to casting, and is a resistor, consisting of a carbon nanotube cement-based transducer. The other sensor can be used to create an external sensing skin and is a capacitor, consisting of a flexible conducting elastomer fabricated from a nanocomposite mix, and deployable in a network setup to cover large structural surfaces. In this paper, we advance the understanding of nanocomposite sensing technologies by investigating the potential of both novel sensors for the dynamic monitoring of civil structures. First, an in-depth dynamic characterization of the sensors using a uniaxial test machine is conducted. Second, their performance at dynamic monitoring of a full-scale concrete beam is assessed, and compared against off-the-shelf accelerometers. Experimental results show that both novel technologies compare well against mature sensors at vibration-based structural health monitoring, showing the promise of nanocomposite technologies for the monitoring of large-scale structural systems.