Skin-like sensor enabled bridge structural health monitoring system

Structural Health Monitoring (SHM) has an important role in the management of transport infrastructure. However, most SHM techniques are based on data obtained from dense networks of point-based sensors (rather than sparse networks of spatial sensors) and so, in relative terms, they are costly to implement. Most commercially available strain sensors have a limited maximum range - typically 1% to 2% - and are not well-suited to providing information of a severe loss of structural integrity. The SENSKIN project develops a dielectric-elastomer and micro-electronics-based skin-like sensor, based on the use of a large highly extensible capacitance sensing membrane and advanced micro-electronic circuitry, for monitoring transport infrastructure - such as bridges. The sensor will provide spatial measurements of strain of more than 10% and is being designed to (a) require low power to operate, (b) be easy to install (c) have a comparable or lower cost than conventional strain sensors, (d) allow simple signal processing, and (e) have the ability to self-monitor and selfreport. The system will support the new and emerging technology of Delay/Disruption- Tolerant Networking to secure that strain measurements acquired will reach the base station even under extreme conditions where communications may be disrupted. SENSKIN also develops a Decision-Support-System (DSS) for proactive condition-based structural interventions under normal operating conditions and reactive emergency intervention following an extreme event. In assessing potential rehabilitation options, the DSS will use the data supplied by the SENSKIN sensors together with advanced structural analysis models, whilst taking account of the lifecycle economic, social and environmental implications. The overall monitoring system will be evaluated and benchmarked on actual bridges of Egnatia Highway (Greece) and Bosporus Bridge (Turkey). This paper describes the concept and principles of the SENSKIN sensing system, and its various components with attention to enduser requirements, specifications and system architecture.