Wireless sensor networks have been identified as a research priority by the European Technology Platform on Smart Systems Integration (EPoSS). Recognising this, the SME's in this Project are seeking EC funding to develop a prototype wide-area wireless sensor network with autonomous nodes containing non-destructive (NDT) sensors, for structural health monitoring (SHM) of large structures, specifically bridges and vessels in petrochemical plant. They have formed a consortium with expertise in a range of technologies needed to optimise solutions and develop this innovative new product.
The aim is to develop an NDT node that is autonomous and self-configuring for optimal performance and requires no maintenance over its operating life. The nodes will be packaged for reliable operation in hazardous environments and will rely on energy harvesting to provide long-term power supply. The wireless communications will allow simple place-and-play usability. The NDT techniques to be implemented are long range ultrasonics for global monitoring of a structure, ACFM for local surface corrosion and cracks, pulse-echo ultrasonics for internal corrosion and tip diffraction ultrasonics for internal cracks. The prototype will show scalability up to very large structures.
Monitoring bridges goes high-tech
Development of a wireless system for bridges will enable authorities to monitor their structural health more efficiently and pre-empt disaster.
Europe's road and rail infrastructure is dotted with bridges that facilitate transport. When these bridges age, however, they become more dangerous as corrosion and cracks make their appearance, requiring constant monitoring and maintenance. Developing new wireless technologies may facilitate the task of monitoring significantly and could help prevent disasters that arise from collapsing bridges.
This was the aim of the EU-funded project 'A wireless network with long range acoustic nodes for total structural health monitoring of bridges' (http://www.wi-health.eu (WI-HEALTH)) . The project worked on replacing periodic inspections with ongoing monitoring through a permanent network of sensors. Such a system is much lighter and more energy efficient than existing solutions for monitoring the health of such structures.
More specifically, WI-HEALTH developed wireless networks that combine long-range ultrasonic and acoustic emission monitoring in autonomously powered nodes to detect bridge defects such as in welded plate structures. It also developed software to drive the structural health monitoring system to identify defects using advanced trend analysis and data processing. Further work involved studying sensor operation, wireless communication systems and renewable energy power options.
After intensive field trials, the project team demonstrated that the system is much more efficient and sensitive than other technologies, showing that defects less than 6 mm deep can be reliably detected. The project's results were disseminated to stakeholders, multimedia and publications, bringing high-tech bridge safety closer to reality.