Embedded Distributed Fiber Optic Strain Measurements for Delamination Detection in Composite Laminates

Date of Award


Degree Name

Ph.D. in Mechanical Engineering


Department of Mechanical and Aerospace Engineering and Renewable and Clean Energy


Advisor: Steven Olson


Aircraft structures are increasingly being fabricated from composite materials due to their light weight and relatively high strength and stiffness. These potential benefits are offset by the introduction of new failure modes, such as internal delamination within the composites. To ensure the integrity and safety of composite aircraft structures, methods to detect internal delamination are needed. In the laboratory, internal delamination damage is often tracked using X-ray computed tomography, but this technique suffers from several drawbacks. To alleviate these concerns, a new approach has been developed which utilizes embedded fiber optics to measure the strains within composite test articles. Measured strains are shown to compare well with finite element predictions under both axial and bending loads. Based on strain differences observed between undamaged and delaminated test articles, the fiber optic strains can also be used to predict the location and approximate length of delamination damage.


Mechanical Engineering, fiber optics, optical strain sensing, carbon composites, delaminations

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Copyright © 2018, author