A fibre-optic time-of-flight laser radar for measuring integral strain in a composite structure

A measurement system based on a sophisticated time-of-flight technique and a single mode optical fibre with internal reflectors has been developed for measuring integral strain inside a composite structure. The strain andspatial resolutions are 0.1 mm and 5 m respectively and the measurement time 1 s. The measurement system is widely tested with different types of composite structures.