Campus Units

Aerospace Engineering, Center for Nondestructive Evaluation

Document Type

Conference Proceeding

Publication Version

Published Version

Publication Date


Journal or Book Title

SPIE Proceedings



First Page




Conference Title

Smart Materials and Nondestructive Evaluation for Energy Systems 2015

Conference Date

March 8–12, 2015


San Diego, CA, United States


Damage to wind turbine blades can, if left uncorrected, evolve into catastrophic failures resulting in high costs and significant losses for the operator. Detection of damage, especially in real time, has the potential to mitigate the losses associated with such catastrophic failure. To address this need various forms of online monitoring are being investigated, including acoustic emission detection. In this paper, pencil lead breaks are used as a standard reference source and tests are performed on unidirectional glass-fiber-reinforced-polymer plates. The mechanical pencil break is used to simulate an acoustic emission (AE) that generates elastic waves in the plate. Piezoelectric sensors and a data acquisition system are used to detect and record the signals. The expected dispersion curves generated for Lamb waves in plates are calculated, and the Gabor wavelet transform is used to provide dispersion curves based on experimental data. AE sources using an aluminum plate are used as a reference case for the experimental system and data processing validation. The analysis of the composite material provides information concerning the wave speed, modes, and attenuation of the waveform, which can be used to estimate maximum AE event – receiver separation, in a particular geometry and materials combination. The foundational data provided in this paper help to guide improvements in online structural health monitoring of wind turbine blades using acoustic emission.


This paper is from Proc. SPIE 9439, Smart Materials and Nondestructive Evaluation for Energy Systems 2015, 94390C (March 27, 2015); doi:10.1117/12.2084527. Posted with permission.


Copyright 2015 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

Copyright Owner

Society of Photo Optical Instrumentation Engineers



File Format



Article Location