OPTICAL FIBER STRAIN TRANSDUCER HAVING A RADIUS OF CURVATURE EQUAL TO OR LESS THAN A CRITICAL RADIUS OF CURVATURE

摘要

A strain transducer (14) is responsive to a deflection thereof for providing a detectable output signal having a characteristic that is expressive of the deflection. The transducer includes an optical fiber having an input port (16) for coupling to a source (18) of optical radiation and an output port (20) for coupling to a receiver (22) of the optical radiation. The optical fiber has at least one region (14') that has a radius of curvature that is equal to or less than a critical radius of curvature for the optical fiber. The at least one region includes a detectable loss in the optical signal in response to being deflected. The optical fiber is disposed within a plane and the detectable loss is shown to be greater for an out-of-plane deflection than for an in-plane deflection. The strain transducer is shown to be especially useful for inclusion within a laminated composite structure, such as a component of an aircraft wing.