On the Effects of the Lateral Strains on the Fiber Bragg Grating Response

Sensors

Marco Lai²  Dimitris Karalekas¹ 

[1] Laboratory of Advanced Manufacturing Technologies and Testing, University of Piraeus, GR-18534 Piraeus, Greece; E-Mail:;École Polytechnique Fédérale de Lausanne (EPFL), LMAF-IGM-STI, CH-1015 Lausanne, Switzerland; E-Mail:

关键词: fiber optic sensor;    optomechanical constant;    biaxial loading;    hydrostatic pressure;    epoxy;    carbon/epoxy;   

DOI  :  10.3390/s130202631

来源: mdpi

【 摘 要 】

In this paper, a combined experimental-numerical based work was undertaken to investigate the Bragg wavelength shift response of an embedded FBG sensor when subjected to different conditions of multi-axial loading (deformation). The following cases are examined: (a) when an isotropic host material with no constrains on planes normal to the embedded sensor's axis is biaxially loaded, (b) when the same isotropic host material is subjected to hydrostatic pressure and (c) when the hydrostatically loaded host material is an anisotropic one, as in the case of a composite material, where the optical fiber is embedded along the reinforcing fibers. The comparison of the experimental results and the finite element simulations shows that, when the axial strain on the FBG sensor is the dominant component, the standard wavelength-shift strain relation can be used even if large lateral strains apply on the sensor. However when this is not the case, large errors may be introduced in the conversion of the wavelength to axial strains on the fiber. This situation arises when the FBG is placed parallel to high modulus reinforcing fibers of a polymer composite.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.