This was a joint project with Professor Gordon Hayward and Dr Alistair McNab of the Centre for Ultrasonic Engineering at Strathclyde University. It investigated the application of wireless communications to interconnect a network of permanently mounted ultrasonic sensors for the structural monitoring of off-shore structures, power and process plant, nuclear power stations and aircraft, where practical monitoring often necessitate the deployment of a large number of sensors and their associated wiring. The connections and wiring are expensive to install, they are susceptible to damage and can compromise the performance of the sensor network; a wireless system is therefore potentially highly advantageous. The project investigated three types of transducer, each having its own area of application with different level of complexity. These can be summarised as follows: (1) a self contained 'matchbox ' sensor for the in-situ measurement of material thickness and the monitoring of crack propagation; (2) An embedded piezoelectric sensor for the passive monitoring of carbon fibre reinforced composite plates using acoustic emission; (3) an array transducer producing imaged data using Lamb waves for shell and plate inspection. Although these transducers are substantially different, the challenge is to design a modular electronic system which will enable them to be integrated within a common communications network and to allow relevant sensor information to be passed back to a central host computer. This involves the implementation of a hierarchy of data acquisition, signal processing and communication functions. The Imperial College part of the project is primarily the design of the array transducer for shell and plate inspection. Fromme, P. et al., Review of Progress in Quantitative NDE, Vol 24, AIP, pp1780-1787, 2005

A cellular system for wireless structural integrity monitoring

Sponsors

EPSRS/HOIS consortium of oil companies