Title

Portable Piezospectroscopy system: non-contact in-situ stress sensing through high resolution photo-luminescent mapping

Authors

Authors

I. Hanhan; E. Durnberg; G. Freihofer; P. Akin;S. Raghavan

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

J. Instrum.

Keywords

Spectrometers; Detection of defects; Data processing methods; THERMAL BARRIER COATINGS; CHROMIUM-DOPED SAPPHIRE; RESIDUAL-STRESS; OXIDATION STRESSES; FLUORESCENCE; SPECTROSCOPY; CALIBRATION; MICROPROBE; EVOLUTION; ALUMINA; Instruments & Instrumentation

Abstract

Through the piezospectroscopic effect, certain photo-luminescent materials, once excited with a laser, produce spectral emissions which are sensitive to the stress or strain that the material experiences. A system that utilizes the piezospectroscopic effect for non-contact stress detection over a material's surface can capture important information on the evolution of mechanical response under various conditions. Therefore, the components necessary for piezospectroscopic mapping and analysis have now been integrated into a versatile and transportable system that can be used with photo-luminescent materials in any load frame or on a variety of structures. This system combines compact hardware components such as a portable laser source, fiber optics, spectrograph, charge-coupled device (CCD), and an X-Y-Z stage (with focusing capabilities) with a series of data analysis algorithms capable of analyzing and outputting high resolution photo-luminescent (PL) maps on-site. Through a proof of concept experiment using a compressed polycrystalline alumina sample with sharp machined corners, this system successfully captured high resolution PL maps with a step size of 28.86 mu m/pixel and located high stress concentrations in critical areas, which correlated closely with the results of a finite element model. This work represents an important step in advancing the portability of piezospectroscopy for in-situ and non-contact stress detection. The instrumentation developed here has strong implications for the future of non-destructive evaluation and non-invasive structural health monitoring.

Journal Title

Journal of Instrumentation

Volume

9

Publication Date

1-1-2014

Document Type

Article

Language

English

First Page

11

WOS Identifier

WOS:000345026000019

ISSN

1748-0221

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