An apparatus and method is described wherein a sensor, such as a mechanical strain sensor, embedded in a fiber core, is "flagged" to identify a preferred orientation of the sensor. The identifying "flag" is a composite material, comprising a plurality of non-woven filaments distributed in a resin matrix, forming a small planar tab. The fiber is first subjected to a stimulus to identify the orientation providing the desired signal response, and then sandwiched between first and second layers of the composite material. The fiber, and therefore, the sensor orientation is thereby captured and fixed in place. The process for achieving the oriented fiber includes, after identifying the fiber orientation, carefully laying the oriented fiber onto the first layer of composite, moderately heating the assembled layer for a short period in order to bring the composite resin to a "tacky" state, heating the second composite layer as the first, and assembling the two layers together such that they merge to form a single consolidated block. The consolidated block achieving a roughly uniform distribution of composite filaments near the embedded fiber such that excess resin is prevented from "pooling" around the periphery of the fiber.
STATEMENT OF GOVERNMENT INTEREST
The United States Government has rights in this invention pursuant to Contract No. DE-AC04-94AL85000 between the United States Department of Energy and the Sandia Corporation for the operation of the Sandia National Laboratories.