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In-situ strain measurements in the plastic deformation regime inside casted parts using fibre-optical strain sensors

A contribution to the production of intelligent parts
  • Florian HeilmeierEmail author
  • Robert Koos
  • Klaus Weraneck
  • Markus Lindner
  • Martin Jakobi
  • Johannes Roths
  • Alexander W. Koch
  • Wolfram Volk
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Abstract

Fibre Bragg Gratings (FBGs) were employed as internal strain sensors within tensile specimens that were machined out of a casted aluminium alloy. Embedded FBGs have the potential to directly measure strains within a casted part for a better understanding of load cases for the part design process. In addition, if the FBGs remain in the part, strains can be measured under real-life conditions and return valuable evidence for health monitoring. The proof of application is provided by the presented tests by comparison of external and internal strain measurements. The step-wise calibration test gives evidence for a linear transition between external straining and internal response by the FBGs and thus a constant conversion factor was obtained. The application in a common tensile test proves a precise strain measurement by the FBGs and their durability until a short time before the specimens failed. These findings form the basis for an application of FBGs within real structural parts and thus the production of intelligent parts in future work. As a conclusion, internal strain measurements using FBGs have the potential to provide additional strain data compared to common methods and hence to improve the design process as well as to monitor casted parts under operating conditions.

Keywords

Optical sensors Tensile test Intelligent part Casting 
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Notes

Acknowledgements

The authors like to thank the Deutsche Forschungsgemeinschaft (DFG) for funding this project under grant No. VO 1487/11-1, KO 2111/11-1 and RO 4145/3-1.

References

  1. 1.
    Wagner JN, Hofmann M, Wimpory R, Krempaszky C, Stockinger M (2014) Microstructure and temperature dependence of intergranular strains on diffractometric macroscopic residual stress analysis. Mater Sci Eng A 618:271–279CrossRefGoogle Scholar
  2. 2.
    Reihle M, Hofmann M, Wasmuth U, Volk W, Hoffmann H, Petry W (2014) In-situ strain measurements during casting using neutron diffraction. Mater Sci Forum 768–769:484–491Google Scholar
  3. 3.
    Drezet J, Mireux B, Szaraz Z, Pirling T (2017) In situ neutron diffraction during casting: determination of rigidity point in grain refined al-cu alloys. Materials 7:1165–1172CrossRefGoogle Scholar
  4. 4.
    Mathar J (1933) Ermittlung von Eigenspannungen durch Messung von Bohrloch-Verformungen. Archiv für das Eisenhüttenwesen 6(7):277–281CrossRefGoogle Scholar
  5. 5.
    Window AL (1992) Strain gauge technology. Elsevier Applied Science, LondonGoogle Scholar
  6. 6.
    Li WY, Cheng CC, Lo YL (2009) Investigation of strain transmission of surface-bonded FBGs used as strain sensors. Sens Actuators A 190:201–207CrossRefGoogle Scholar
  7. 7.
    Manner S (2016) Validation of a hybrid Sensor Network for Helicopter Rotor Blades, Dissertation. Technische Universität, MünchenGoogle Scholar
  8. 8.
    de Oliviera R, Ramos CA, Marques AT (2008) Health monitoring of composite structures by embedded FBG and interferometrie Fabry–Pérot sensors. Comput Struct 86:340–346CrossRefGoogle Scholar
  9. 9.
    Weraneck K, Heilmeier F, Lindner M, Graf M, Jakobi M, Volk W, Roths J, Koch AW (2016) Strain measurement in aluminium alloy during the solidification process using embedded fibre bragg gratings. Sensors 16:1853–1870CrossRefGoogle Scholar
  10. 10.
    Lindner M, Tunc E, Weraneck K, Heilmeier F, Volk W, Jakobi M, Koch AW, Roths J (2018) Regenerated Bragg grating sensor array for temperature measurements during an aluminium casting process. IEEE Sens 18(13):5352–5360CrossRefGoogle Scholar
  11. 11.
    DIN 50125:2016-12 (2016) Prüfung metallischer Werkstoffe - Zugproben. Deutsches Institut für Normung e.VGoogle Scholar
  12. 12.
    ISO 3522:2007 (2007) Aluminium and aluminium alloys-Castings—Chemical composition and mechanical properties. International Organization for StandardizationGoogle Scholar
  13. 13.
    BDG (2017) Bundesverband der Deutschen Gießereiindustrie: Sand- und Kokillenguss aus Aluminium. Bundesverband der Deutschen Gießerei-Industrie, DüsseldorfGoogle Scholar
  14. 14.
    ISO 6892-1:2016 (2016) Metallic materials—tensile testing—part 1: method of test at room temperature. International Organization for StandardizationGoogle Scholar
  15. 15.
    Kashyap R (1997) Fiber Bragg gratings, 2nd edn. Academic Press, LondonGoogle Scholar
  16. 16.
    Erdogan T (1997) Fiber grating spectra. J Lightwave Technol 15(8):1277–1294CrossRefGoogle Scholar
  17. 17.
    Rao Y (1997) In-fibre Bragg grating sensors. Meas Sci Technol 8:355–375CrossRefGoogle Scholar
  18. 18.
    Othonos A (1997) Fiber Bragg Gratings. Rev Sci Instrum 68:4309–4341CrossRefGoogle Scholar
  19. 19.
    Jülich F, Aulbach L, Wilfert A, Kratzer P, Kuttler R, Roths J (2013) Gauge factors of fibre Bragg grating strain sensors in different types of optical fibres. Meas Sci Technol 24:094007 (7pp)CrossRefGoogle Scholar
  20. 20.
    Morey WW, Meltz G, Glenn WH (1990) Fiber optic Bragg grating sensors. Proc SPIE 1169:98–107CrossRefGoogle Scholar
  21. 21.
    Werneck MM, Allil RCSB, Ribeiro BA, de Nazaré FVB (2013) A guide to fiber bragg grating sensors. In: Cuadrado-Laborde C (ed) Current trends in short- and long-period fiber gratings. IntechOpen.  https://doi.org/10.5772/54682. Available from: https://www.intechopen.com/books/current-trends-in-short-and-long-periodfiber-gratings/a-guide-to-fiber-bragg-grating-sensors
  22. 22.
    Othonos A (1999) Fibre Bragg grating: fundamentals and applications in telecommunications and sensing. Artech House, London, pp 352–356Google Scholar
  23. 23.
    Gafsi R, El-Sherif MA (2000) Analysis of induced-birefringence effects on fiber Bragg gratings. Opt Fiber Technol 6:299–323CrossRefGoogle Scholar
  24. 24.
    Urban F, Kadlec J, Vlach R, Kuchta R (2010) Design of a sensor based on optical fiber bragg grating lateral deformation. Sensors (Basel, Switzerland) 10:11212–11225CrossRefGoogle Scholar
  25. 25.
    MATLAB (2018) Signal Processing Toolbox User’s Guide Release 2016b, The MathWorks, Inc., Natick, Massachusetts, United StatesGoogle Scholar
  26. 26.
    MATLAB (2018) Image Processing Toolbox User’s Guide, Release 2016b. The MathWorks Inc, Natick, Massachusetts, United StatesGoogle Scholar
  27. 27.
    Shen Y-L (1997) Combined effects of microvoids and phase contiguity on the thermal expansion of metal-ceramic composites. Mater Sci Eng A 237:102–108CrossRefGoogle Scholar
  28. 28.
    Müller MS, Buck TC, El-Khozondar HJ, Koch AW (2009) Shear strain influence on fiber Bragg grating measurement systems. J Lightwave Technol 27(23):5223–5229CrossRefGoogle Scholar

Copyright information

© German Academic Society for Production Engineering (WGP) 2019

Authors and Affiliations

  1. 1.Institute of Metal Forming and CastingTechnical University of MunichGarchingGermany
  2. 2.Research Neutron Source Heinz Maier-LeibnitzTechnical University of MunichGarchingGermany
  3. 3.Institute for Measurement Systems and Sensor TechnologyTechnical University of MunichMunichGermany
  4. 4.Photonics LaboratoryMunich University of Applied SciencesMunichGermany

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