Strain Transfer Capability of Strain Sensing Optical Fiber Cable and Its Measurement Method

摘要

The frequency shift of Brillouin scattering in optical fiber is a promising technology for Structural Health Monitoring (SHM), but the progress of it at present is reduced by the unavailability of qualified sensor products specifically aimed at such application. Commercial available optical fiber cable products are not generally suited for strain measurements since they are designed to decouple the fibers from any applied strains. Till now no special parameter is defined to weight the strain measurement capability of strain sensing optical fiber cable. In this paper, a new parameter called strain transfer capability is defined which is found very useful to characterize the performance of optical fiber cable for strain sensing; and the measurement method of it is also suggested. Measurement results on different sensing products are presented. Some strain sensing optical fiber cables have special structure and excellent strain transfer capability are developed, which are considered suitable for strain measurements.