High repetition-rate full-spectrum interrogation of FGB sensors for dynamic measurements in composite laminates

This paper presents a new means for collecting fiber Bragg grating (FBG) data during drop tower measurements used to assess damage to composite structures. The high repetition-rate collection process reveals transient features that cannot be resolved in quasi-static measurements. The experiments made at a repetition rate of about 500 Hz show that the detected FBG spectrum broadens for a short period of time and relaxes quickly to a narrower static state. Furthermore, this relaxation time increases dramatically as the strike count increases. The information gained by such measurements will enhance the ability to characterize and distinguish failure modes and predict remaining lifetime in composite laminate structures.

[1]  Ahmet S. Yigit,et al.  On the impact of a spherical indenter and an elastic-plastic transversely isotropic half-space , 1994 .

[2]  Federico Casagrande,et al.  From the reflected spectrum to the properties of a fiber Bragg grating: a genetic algorithm approach with application to distributed strain sensing. , 2002, Applied optics.

[3]  Kara Peters,et al.  Global-local Assessment of Low-velocity Impact Damage in Woven Composites , 2007 .

[4]  Nobuo Takeda,et al.  A new approach to predicting multiple damage states in composite laminates with embedded FBG sensors , 2005 .

[5]  Maurice Whelan,et al.  Residual strain measurement and impact response of optical fibre Bragg grating sensors in fibre metal laminates , 2001 .

[6]  Kara Peters,et al.  Genetic algorithm for the reconstruction of Bragg grating sensor strain profiles , 2004 .

[7]  Chao Lu,et al.  High-speed fibre Bragg grating sensor interrogation using dispersion compensation fibre , 2008 .

[8]  M. A. Zikry,et al.  In-situ impact-induced damage assessment of woven composite laminates through a fibre Bragg grating sensor network , 2009, The Aeronautical Journal (1968).

[9]  M. Blondel,et al.  Autocorrelation demodulation technique for fiber Bragg grating sensor , 2004, IEEE Photonics Technology Letters.

[10]  Eric Udd,et al.  Failure mechanisms of fiber optic sensors placed in composite materials , 2005, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[11]  S. Monteiro,et al.  Evaluation of repeated low energy impact damage in carbon–epoxy composite materials , 2005 .

[12]  L. Louca,et al.  Structural response of impact-damaged composite panels , 2005, Proceedings of OCEANS 2005 MTS/IEEE.