Strain Mapping of Bolted Composite Airframes using Fiber Optic Sensors


Composites are used as structural materials for aerospace applications due to their high strengthto-weight ratio, low weight and high corrosion resistance compared to metals. However, due to their anisotropic nature, damage initiation and propagation is far more complex. Fiber optic sensors provide a robust means of non-destructive evaluation of high performance composite materials during service. In this research, fiber optic sensors are used to detect strain distribution around fastener holes in a composite airframe. Composite panels are manufactured using carbon fiber/toughened epoxy (IM7/977-3) prepregs and holes are drilled to accommodate Hi-Lok fastener pins. Data from fiber optic sensors is used to detect changes in strain distribution around the hole due to unbalanced mechanical loads. A comprehensive three-dimensional finite element model is developed for simulating strain distribution around the hole, under tensile load. The optimal locations for bonding the optical fibers are estimated from the measured strain distribution. The sensor output is compared with the result of numerical simulation.

Meeting Name

Composites and Advanced Materials Expo: Combined Strength. Unsurpassed Innovation, CAMX 2014 (2014: Oct. 13-16, Orlando, FL)


Electrical and Computer Engineering

Second Department

Mechanical and Aerospace Engineering

Keywords and Phrases

Aerospace applications; Airframes; Carbon fibers; Corrosion resistance; Fiber bonding; Fiber optics; Fibers; Finite element method; Locks (fasteners); Nondestructive examination; Optical fibers; Strength of materials; Structural frames; Structural metals, Composite airframe; Damage initiation; High-performance composite materials; Non destructive evaluation; Optimal locations; Strain distributions; Strength to weight ratio; Three dimensional finite element model, Fiber optic sensors

Document Type

Article - Conference proceedings

Document Version


File Type





© 2014 The Composites and Advanced Materials Expo (CAMX), All rights reserved.

Publication Date

01 Oct 2014

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