Curvature measurements

New developments are reported regarding the fibreoptic curvature gauge proposed recently. Advantages in measuring curvature, rather than strain, are presented. In contrast to direct sensors ofstrain where reliable structural strain transmission onto the sensor must be assured, the curvature gauge is unaffected by mechanical properties of intermediate objects such as the cushioning effect ofthe fibre protective coating, adhesives, resin, etc. Furthermore, curvatures can be measured anywhere in the structure's cross section, including along the neutral axis where there is no strain in bending. This simplifies the process of embedding sensors and the interpretation of the signals obtained. Curvature measurements are particularly suitable for thinner structures where extreme resolution in measuring strain would be required.