Abstract
The accurate shape sensing method is expected to be useful for large scaled structural health monitoring of aircraft
structures. This research is trying to construct a high-accuracy structural shape identification method using distributed
strain data from an optical fiber strain sensing system; pulse-prepump Brillouin optical time domain analysis (PPP-BOTDA)
system. In addition, the optical fiber can be embedded in composite material, which has recently been applied
for the structural material of aircrafts or some other large-scaled structures. In this paper, we carried out an experiment
using composite specimen with an embedded optical fiber to show the characteristics of distributed data from PPP-BOTDA
system. Moreover, a simple inverse analysis, which derives deformation from measured distributed strain data,
was also carried out. From results of these verifications, the strain data from PPP-BOTDA system showed reasonable
distributions suitable to the deformation of specimen. At the same time, it was also shown that, in using the distributed
strain data for shape identification algorithm, we have to consider the changes in distribution profile at the discontinuous
points of strain distribution along the fiber.
