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Residual Strains using Integrated Continuous Fiber Optic Sensing in Thermoplastic Composites and Structural Health Monitoring

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Abstract

The evolution of spatially resolved internal strain/stress during the manufacturing of thermoplastic composites and subsequent relaxation from water intake are evaluated using an in-situ fiber optic sensor corresponding to a coated optical glass fiber with a nominal diameter of 160 μm. Unidirectional carbon fiber-polyamide 6 composites are produced using compression molding with an embedded fiber optic for strain measurement. The distributed fiber optic based strain sensor is placed in an arrangement to capture 0, 45, and 90° strains in the composite to resolve in-plane strain tensor. Strains are monitored in the direction of fiber optic sensor along its length at high resolution during the various stages of compression molding process. Results indicate considerable internal strains leading to residual stress at the end of processing step along the off-axis (45°) and transverse (90°) directions, and small strains in the carbon fiber pre-preg (0°) direction. At the end of compression molding process, an average of 7000 and 10,000 compressive micro-strains are obtained for residual state of strain in the off-axis and transverse direction. Since water/moisture infusion affects the mechanical properties of polyamide-6 matrix resin, these composite panels with embedded sensors targeted for marine applications are monitored in a water bath at 40 °C simulating accelerated testing conditions. Using the same fiber optic sensor based technique, the strain relaxation was observed during water uptake demonstrating in-situ strain monitoring during both manufacturing and subsequent composite implementation/application environment. The technique presented in this paper shows the potential of optimizing time-temperature-pressure protocols typically utilized in thermoplastic manufacturing, and continuous life-cycle monitoring of composite materials using a small diameter and inexpensive distributed fiber optic sensing.

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References

  1. Ajovalasit A (2011) Advances in strain gauge measurement on composite materials: strain measurement on composite materials. Strain 47(4):313–325

    Article  Google Scholar 

  2. Pan B, Qian K, Xie H, Asundi A (2009) Two-dimensional digital image correlation for in-plane displacement and strain measurement: a review. Meas Sci Technol 20(6):62001

    Article  Google Scholar 

  3. Soh C-K, Yang Y, Bhalla S (2012) Smart materials in structural health monitoring, control and biomechanics. Zhejiang Univ. Press, Hangzhou

    Book  Google Scholar 

  4. De Baere I, Luyckx G, Voet E, Van Paepegem W, Degrieck J (2009) On the feasibility of optical fiber sensors for strain monitoring in thermoplastic composites under fatigue loading conditions. Opt Lasers Eng 47(3):403–411

    Article  Google Scholar 

  5. Sorensen L, Gmür T, Botsis J (2006) Residual strain development in an AS4/PPS thermoplastic composite measured using fiber Bragg grating sensors. Compos Part Appl Sci Manuf 37(2):270–281

    Article  Google Scholar 

  6. Kuang K, Kenny R, Whelan MP, Cantwell WJ, Chalker PR (2001) Embedded fiber Bragg grating sensors in advanced composite materials. Compos Sci Technol 61(10):1379–1387

    Article  Google Scholar 

  7. Grave JHL, Håheim ML, Echtermeyer AT (2015) Measuring changing strain fields in composites with Distributed Fiber-Optic Sensing using the optical backscatter reflectometer. Compos Part B Eng 74:138–146

    Article  Google Scholar 

  8. Uchida S, Levenberg E, Klar A (2015) On-specimen strain measurement with fiber optic distributed sensing. Measurement 60:104–113

    Article  Google Scholar 

  9. Sánchez DM, Gresil M, Soutis C (2015) Distributed internal strain measurement during composite manufacturing using optical fiber sensors. Compos Sci Technol 120:49–57

    Article  Google Scholar 

  10. Pedrazzani JR, Klute SM, Gifford DK, Sang AK, Froggatt ME (2012) Embedded and surface mounted fiber optic sensors detect manufacturing defects and accumulated damage as a wind turbine blade is cycled to failure. Luna Innovations Incorporated, Baltimore

  11. Pedrazzani JR, Castellucci M, Sang AK, Froggatt ME, Klute SM, Gifford DK (2012) Fiber optic distributed strain sensing used to investigate the strain fields in a wind turbine blade and in a test coupon with open holes. In Proceedings of the 44th International SAMPE Tech. Conf, pp 22–25

  12. Klute SM, Sang AK, Gifford DK, Froggatt ME (2012) Appendix H: Defect detection during manufacture of composite wind turbine blade with embedded fiber optic distributed strain sensor’. FINAL TECHNICAL REPORT, Effect of Manufacturing-Induced Defects on Reliability of Composite Wind Turbine Blades, U.S. Department of Energy, Award No. DE-EE0001374 ARRA Funding

  13. Klute SM, Metrey DR, Garg N, Rahim NAA (2016) In-situ structural health monitoring of composite-overwrapped pressure vessels. SAMPE J 52(2):7–17

    Google Scholar 

  14. Kreger ST, Gifford DK, Froggatt ME, Soller BJ, Wolfe MS (2006) High resolution distributed strain or temperature measurements in single-and multi-mode fiber using swept-wavelength interferometry. OFS Technical Digest, Optical Fiber Sensors, Paper ThE42

  15. Soller B, Gifford D, Wolfe M, Froggatt M (2005) High resolution optical frequency domain reflectometry for characterization of components and assemblies. Opt Express 13(2):666–674

    Article  Google Scholar 

  16. Soller BJ, Wolfe M, Froggatt ME (2005) Polarization resolved measurement of Rayleigh backscatter in fiber-optic components. Paper NWD3. OFC Tech Digest, Los Angelos,

  17. Minakuchi S, Umehara T, Takagaki K, Ito Y, Takeda N (2013) Life cycle monitoring and advanced quality assurance of L-shaped composite corner part using embedded fiber-optic sensor. Compos Part A 48:153–161

    Article  Google Scholar 

  18. Frieden J, Cugnoni J, Botsis J, Gmur T, Coric D (1905-1912) High-speed internal strain measurements in composite structures under dynamic load using embedded FBG sensors. Compos Struct 2010:92

    Google Scholar 

  19. Di Sante R (2015) Fibre Optic Sensors for Structural Health Monitoring of Aircraft Composite Structures: Recent Advances and Applications. Sensors 15:18666–18713

    Article  Google Scholar 

  20. Luna Technologies (2014) Optical Distributed Sensor Interrogator (Model ODiDI-B) - Data Sheet. Roanoke, VA

  21. Parlevliet PP, Bersee HEN, Beukers A (2006) Residual stresses in thermoplastic composites—A study of the literature—Part I: Formation of residual stresses. Compos Part Appl Sci Manuf 37(11):1847–1857

    Article  Google Scholar 

  22. Mulle M, Wafai H, Yudhanto A, Lubineau G, Yaldiz R, Schijve W, Verghese N (2016) Process monitoring of glass reinforced polypropylene laminates using fiber Bragg gratings. Compos Sci Technol 123:143–150

    Article  Google Scholar 

  23. Parlevliet PP, Bersee HEN, Beukers A (2007) Residual stresses in thermoplastic composites – a study of the literature. Part III: Effects of thermal residual stresses. Compos Part Appl Sci Manuf 38(6):1581–1596

    Article  Google Scholar 

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Acknowledgments

Professor Penumadu would like to acknowledge the support of the Office of Naval Research Solid Mechanics Program through ONR Award No: N00014-16-1-2765 and the Institute for Advanced Composites Manufacturing Innovation from the US Department of Energy for various ongoing carbon fiber composite related research projects in his research group and this work benefitted greatly from both infrastructure and intellectual resources. IFREMR facilitated the visit of Mr. Mael Arhant through financial support to Dr. Davies. Authors appreciate the support of LUNA and technical suggestions of Mr. Matt Davis and Dr. Stephen Young.

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Authors and Affiliations

  1. The University of Tennessee, Tickle College of Engineering, Knoxville, TN, USA

    M. Arhant, N. Meek & D. Penumadu

  2. Ifremer, Marine and Structures laboratory, Brest, France

    M. Arhant & P. Davies

  3. CEE Department, University of Tennessee, 325 John D. Tickle Building, Knoxville, TN, 37996-2313, USA

    D. Penumadu

  4. Luna Technologies, Blacksburg, VA, USA

    N. Garg

Authors
  1. M. Arhant
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  2. N. Meek
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  3. D. Penumadu
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  4. P. Davies
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  5. N. Garg
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Correspondence to D. Penumadu.

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Arhant, M., Meek, N., Penumadu, D. et al. Residual Strains using Integrated Continuous Fiber Optic Sensing in Thermoplastic Composites and Structural Health Monitoring. Exp Mech 58, 167–176 (2018). https://doi.org/10.1007/s11340-017-0339-2

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  • DOI: https://doi.org/10.1007/s11340-017-0339-2

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