Stress sensor based on periodically inserted color-changing tactile films to detect mishandling fiber optic cables

摘要

The present invention is a fiber optic cable which uses pressure sensitive films or tactile films in order to detect areas on a fiber optic cable where excessive loads have been applied or experienced. A plurality of strips of tactile film or pressure sensitive film (35) are inserted, at regular intervals, throughout the fiber optic cable structure in a fashion similar to that of swellable tape (34). The films are located between the buffer tube(s) (32) and the outer jacket (36) of the cable or between the fibers and the outer jacket of the cable. This intermittent use decreases the overall cost and weight of the cable, over using a continuous length of tactile film. It is also desirable to have the tactile or pressure sensitive film with corrugated folds along the width of the film. This corrugation provides a much higher sensitivity to loads experienced by the cables due to more "aggressive" deformation of the film during buckling.