There has been considerable discussion in the technical community on a number of questions concerned with smart materials and structures, such as what they are, whether smart materials can be considered a subset of smart structures, whether a smart structure and an intelligent structure are the same thing, etc. This discussion is both fueled and confused by the technical community due to the truly multidisciplinary nature of this new field. Smart materials and structures research involves so many technically diverse fields that it is quite common for one field to completely misunderstand the terminology and start of the art in other fields. In order to ascertain whether a consensus is emerging on a number of questions, the technical community was surveyed in a variety of ways including via the internet and by direct contact. The purpose of this survey was to better define the smart materials and structures field, its current status and its potential benefits. Results of the survey are presented and discussed. Finally, a formal definition of the field of smart materials and structures is proposed.

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The concept of the smart structure integrates structural engineering, sensing, control systems and actuation to provide a mechanical assembly which is capable of responding to its environment and/or loading conditions. The realisation of the smart structure requires integration of skills in a variety of scientific and engineering disciplines ranging from mechanical engineering through materials science into signal processing, data analysis, sensing and actuation.The sensing technology must have a number of key features of which the ability to take distributed measurements of various parameters throughout the structure is paramount. Fibre optics technology therefore promises to have a significant role to play in the evolution of the smart structures concept. This paper analyses this role in detail, presents an assessment of the current state-of-the art in fibre optic technology related to smart structures and presents a scenario for future developments. INrRODUCTIONThe smart structure integrates mechanical engineering, control systems, signal processing and actuation in a way which can be visualised with reference to Figure 1 . The essential concepts are that the actuators and sensors are embedded within the actual structure and therefore form an integral part of its behavioural characteristics. The smart structure may then respond by adapting its dimensions, its stiffness, its vibrational characteristics, its damping constant, etc, in response to environmental and/or loading conditions. The realisation of a truly smart or adaptive structure requires advanced technology in sensing, processing, control and actuation and to date they have only been brought together at a relatively simplistic level for specialised applications such as space vehicles 1.The first step in the realisation of the generalised smart structure is the incorporation of the necessary sensor arrays to obtain the essential data concerning the state of the structure. In general this requires precision distributed measurements of the strain, temperature and sometimes chemical composition throughout the structure. Careful analysis of loading requirements and the structural characteristics can limit the number of sensory elements required, but in general, a complex sensing array is essential. This paper focuses on the needs in this sensor array and discusses these needs with reference to the properties of fibre optics systems, thereby demonstrating that fibre optics will have an important but not exclusive role to play in the evolution of smart structures.Potential applications for smart structures may be viewed either by the industrial sector under consideration or through the properties of the materials from which a particular structure is fabricated. There are potential applications in aerospace (especially for zero gravity structures), civil engineering, marine engineering, automotive engineering, and in the longer term, when the technology costs are pruned, in consumer products such as toys, leisure goods and domestic appliances. A discussion ba...

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