Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
The use of modern instruments in structural analysis : A review of DIC and FBG sensors.
Submission Author:
Vinicius Vieira , SP , Brazil
Co-Authors:
Vinicius Vieira, Rodolpho Gardenal Fabbre, Bruno Agostinho Hernandez, EDSON CAPELLO SOUSA, Marcelo Sampaio Martins
Presenter: Bruno Agostinho Hernandez
doi://10.26678/ABCM.COBEM2023.COB2023-1544
Abstract
When information about the state of stress and strain in a structure is needed, electric strain gauges are generally used due to their low cost, availability, and versatility. However, this technique has some disadvantages such as sensitivity to electrical interference, it works only within certain temperature ranges, it is very sensitive to mechanical impacts and high-cycle vibrations, as well as being difficult to use in remote locations. Consequently, other strain measurement sensors have emerged, such as the Digital Image Correlation (DIC) and Fiber Bragg Grating (FBG) sensors. The aim of this study was to evaluate the state of the art of DIC and FBG. This evaluation was carried out through a review of a wide range of recent papers on these methodologies, as both measurement modes are highly prominent with more than 30,000 citations in articles published since 2022. DIC is a measurement method that is performed using a digital image correlation technique of the surface of the structure while it is subjected to loading. In this analyzed excerpt, there are randomly spaced points, so the software is able to analyze these points captured by CCD cameras before, during, and after loading, and thus it is possible to analyze the effects of deformations on the desired part, thus quantifying the deformations at the location. This method has numerous advantages such as being non-invasive, non-destructive, enabling 2D and 3D deformation analysis, capable of measuring large and small objects, among others. The FBG sensor is an alternative for the analysis of stress, strain, pressure, temperature, vibrations, among other parameters. It is an optical sensor that has a pattern of refractive index modulation within an optical fiber, which functions as a kind of wavelength filter, called Bragg Gratings. Based on the stimulus provided to the structure and consequently to the fiber, one can analyze the wavelength spectra initially and after the reflections. The frequency change due to perturbations is detected and interpreted to provide accurate information about the property of the structure being monitored. One of its most advantageous properties is the ability to measure multiple parameters at once (multiplexing), not being a destructive test, low weight, easy maintenance, rapid/precise responses, high sensitivity, and immunity to electromagnetic interference. Thus, it is interesting to enable other sensing methods in deformation analysis, such as DIC and FBG, given their advantages over strain gauges.
Keywords
FBG sensor, DIC, structural analysis
