PRODUCTION AND USE OF AN INTERFEROMETRIC OPTICAL STRAIN-GAUGE WITH COMPARISON TO CONVENTIONAL TECHNIQUES

The use of optical fibres in transducers has recently attracted much i nterest and the adoption of optical techniques in strain detection is growing due to the reliability and accuracy they can offer in harsh en vironmental conditions (strong electromagnetic fields, high temperatur e, corrosive chemicals, etc.) where the conventional electrical strain gauges often fail. In this paper an optical strain gauge based on a t rue fibre Michelson interferometric scheme is developed and tested. Th e discrete optical strain gauge is realised by embedding the optical f ibre sensing leads into a resin support which allows its easy installa tion and use. The related static and dynamic behaviours are investigat ed and compared with those of similar optical sensing systems either d irectly bonded to the structure or embedded in composite laminates. Co mparisons are also made with theoretical predictions and measurements supplied by semiconductor electrical strain gauges. (C) 1997 Elsevier Science Ltd.