@article{van hoe_oman_van steenberge_stan_schultz_peters_2017, title={High-Speed Interrogation of Multiplexed Fiber Bragg Gratings With Spectral Distortion}, volume={17}, ISSN={["1558-1748"]}, DOI={10.1109/jsen.2017.2750327}, abstractNote={Fiber Bragg grating (FBG) sensors can be multiplexed in large numbers to monitor the performance of large structures. This paper addresses the collection of FBG reflection spectra from wavelength division multiplexed sensors at fast acquisition rates. The spectral and temporal resolution is first derived as a function of the tunable filter and measurement system properties. The method is applied to impact loading investigations of a stiffened composite skin panel. The reflected spectrum of each FBG in an array, embedded in the panel, is collected at 100 kHz during the impact events with a spectral resolution down to 40 pm. Visualization of the FBG responses to these impact events, including the presence of spectral distortion in some FBG spectra, is presented. Future analyses based on the full-spectral data sets can enable the assessment of the localized progression of internal damage in such structures.}, number={21}, journal={IEEE SENSORS JOURNAL}, author={Van Hoe, Bram and Oman, Kyle G. and Van Steenberge, Geert and Stan, Nikola and Schultz, Stephen M. and Peters, Kara J.}, year={2017}, month={Nov}, pages={6941–6947} }
 @article{oman_van hoe_aly_peters_van steenberge_stan_schultz_2015, title={Instrumentation of integrally stiffened composite panel with fiber Bragg grating sensors for vibration measurements}, volume={24}, ISSN={["1361-665X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938117649&partnerID=MN8TOARS}, DOI={10.1088/0964-1726/24/8/085031}, abstractNote={We evaluate the performance of fiber Bragg grating (FBG) sensors for the measurement of dynamic strains in complex composite structures. The particular structure used in this study is an integrally stiffened composite panel for which the stiffeners and skin are fabricated in a single layup and cure process. Surface-mounted FBG sensors are bonded to the panels after curing, whereas embedded FBG sensors are successfully incorporated during the fabrication process. A finite element model was also constructed of the stiffened panel. The panels were subjected to repeated impacts and the post-impact vibration response of the panel was measured through the FBG sensor responses. Little change to the global response of the panel was observed after the repeated impacts, through the dynamic response of the surface-mounted FBGs. Pulsed phase thermography and micro-computer-tomography imaging of the panel confirmed that the damage was localized near the impact locations, producing negligible changes to the global response of the panel. All of the embedded FBG sensors survived the fabrication and multiple impacts; however, as these were embedded close to the neutral axis of the panel, they were not very sensitive to the vibration modes. Excitation of the panel near the first natural frequency did produce a measurable response in the FBG sensors, confirming their functionality.}, number={8}, journal={SMART MATERIALS AND STRUCTURES}, author={Oman, Kyle and Van Hoe, Bram and Aly, Karim and Peters, Kara and Van Steenberge, Geert and Stan, Nikola and Schultz, Stephen}, year={2015}, month={Aug} }
 @article{webb_oman_peters_stan_chadderdon_selfridge_schultz_2014, title={Localized measurements of composite dynamic response for health monitoring}, volume={9062}, ISSN={["1996-756X"]}, DOI={10.1117/12.2045255}, abstractNote={We demonstrate the measurement of and applications for full-spectral measurements collected from FBG sensors in dynamic loading environments. The measurement of the dynamic response of a laminated plate to an impact event highlights the information gained during the event as compared to after the event. The measurement of damage induced spectral distortion in a thin plate during vibration loading demonstrates the capability of separating spectral distortion due to multiple effects, including damage and vibration loading. Finally, the measurement of the change in dynamic response of an adhesively bonded joint highlights the capability to measure the progression of fatigue damage. Confirmation that the change in FBG response is due to fatigue damage is performed through independent pulsed phase thermography imaging of the adhesively bonded joint.}, journal={SMART SENSOR PHENOMENA, TECHNOLOGY, NETWORKS, AND SYSTEMS INTEGRATION 2014}, author={Webb, Sean and Oman, Kyle and Peters, Karsa and Stan, Nikola and Chadderdon, Sspencer and Selfridge, Richard and Schultz, Stephen}, year={2014} }