Low Velocity Impact of Optical Fiber Embedded Laminated Graphite/Epoxy Panels. Part II: Micro-Scale

Abstract

Optical Microscopy and Scanning Electron Microscopy are used to investigate the micro-crack distribution in the vicinity of optical fibers embedded in laminated graphite/epoxy plates subjected to low velocity impact. The test matrix consists of six different types of optical fibers embedded in [90₂/0₄/OF(0)/0₄/90₂], [90₆/OF(0)/90₆], [(45/-45)₃/OF(0)/(-45/45)₃] AS4/3501-6 plates. The results show that the optical fiber diameter and coating influence the micro-crack distribution in the [90₂/0₄/OF(0)/0₄/90₂], [90₆/OF(0)/90₆], [(45/-45)₃/OF(0)/(-45/45)₃] plates, and that the host damage is insensitive to the presence of the optical fiber for [90₆/OF(0)/90₆] laminates. The results further indicate that optical fibers less than 100 μm in diameter do not alter the indigenous micro-crack distribution for these material systems and this optical fiber placement.

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