A continuous wave radar technique for structural health monitoring

Radar is a technique commonly used to determine the instantaneous distance between moving objects. This paper proposes the application of a frequency-modulated continuous wave technique for the purpose of drift sensing in a structural health monitoring context. This context requires the measurement of interstorey drift ratios to determine the damage to a structure. Any structural health monitoring system must be able to detect interstorey displacement accurately enough to ensure that any potentially damaging events are detected. The primary motivation for the development of this technique is to negate the limitations of current drift sensing methods (such as accelerometers and line-scan cameras). The proposed system is simulated, and it is found that with sufficiently large frequency sweep bandwidth, errors in displacement tracking can be as low as 0.26% of the actual displacement, with a minimum detectable displacement of 0.1%. These results justify the further development of a hardware prototype.