Fiber optic vibration sensing and neural networks methods for prediction of composite beam delamination

Gilbert W. Sanders; Farhad Akhavan; Steve E. Watkins; K. Chandrashekhara

doi:10.1117/12.275710

6 June 1997 Fiber optic vibration sensing and neural networks methods for prediction of composite beam delamination

Gilbert W. Sanders, Farhad Akhavan, Steve E. Watkins, K. Chandrashekhara

Proceedings Volume 3041, Smart Structures and Materials 1997: Smart Structures and Integrated Systems; (1997) https://doi.org/10.1117/12.275710
Event: Smart Structures and Materials '97, 1997, San Diego, CA, United States

Abstract

Extrinsic Fabry-Perot interferometric (EFPI) fiber optic sensors were used to characterize delamination size and location in laminated composite bemas. Six eight-ply glass/epoxy composite beams, each 26.04 cm long and 2.33 cm wide, were fabricated with five midplane delamination sizes ranging from 1.27 cm to 6.35 cm long. The five delaminated beams as well as undamaged beams were tested for their first five modal frequencies. The modal frequencies shifted with changes of delamination size and location. The EFPI fiber optic sensors measured identical model frequencies as piezoelectric ceramic sensors. However, EFPI fiber optic sensors showed more sensitivity and better signal-to-noise ratios. Analytical classical beam theory and finite element methods validated the EFPI modal frequency measurements. A feedforward backpropagation neural network predicted the size and location of a prescribed mid-plane delamination in the composite beam using the EFPI fiber optic sensor modal frequency measurements. Modal frequency data sets from classical beam theory were used for training and testing the network. The delamination size and location predictions from the neural network had an average error of 5.9% and 4.7% respectively.

Citation Download Citation

Gilbert W. Sanders, Farhad Akhavan, Steve E. Watkins, and K. Chandrashekhara "Fiber optic vibration sensing and neural networks methods for prediction of composite beam delamination", Proc. SPIE 3041, Smart Structures and Materials 1997: Smart Structures and Integrated Systems, (6 June 1997); https://doi.org/10.1117/12.275710

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available