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原文传递 Noncontact Strain Mapping Using Laser-Induced Fluorescence from Nanotube-Based Smart Skin

题名：	Noncontact Strain Mapping Using Laser-Induced Fluorescence from Nanotube-Based Smart Skin
正文语种：	英文
作者：	Peng Sun, S.M.ASCE1; Sergei M. Bachilo2; Ching-Wei Lin3; R. Bruce Weisman4; and Satish Nagarajaiah, F.ASCE5
作者单位：	1Graduate Research Assistant, Dept. of Civil and Environmental Engineering and Smalley-Curl Institute, Rice Univ., 6100 Main St., Houston, TX 77005. 2Research Scientist, Dept. of Chemistry and Smalley-Curl Institute, Rice Univ., 6100 Main St., Houston, TX 77005. 3Graduate Research Assistant, Dept. of Chemistry and Smalley-Curl Institute, Rice Univ., 6100 Main St., Houston, TX 77005. 4Professor, Dept. of Chemistry, Dept. of Material Science and NanoEngineering, Smalley-Curl Institute, Rice Univ., 6100 Main St., Houston, TX 77005. 5Professor, Dept. of Civil and Environmental Engineering, Dept. of Material Science and NanoEngineering, Smalley-Curl Institute, Rice Univ., 6100 Main St., Houston, TX 77005 (corresponding author).
关键词：	Two-dimensional (2D) strain map; Noncontact strain sensing; Carbon nanotubes; Shortwave infrared fluorescence; Structural discontinuity; Stress/strain concentration; Nondestructive evaluation; Finite-element analysis
摘要：	Stress fields around structural discontinuities such as cracks usually cause complex but distinct strain contours/maps when structures are subjected to load. Hence, mechanical strain on structural surfaces can provide useful information on the condition of materials, including damage location and severity. The phenomena of stress concentration or strain concentration around discontinuities (such as holes and cracks) can be used to perform nondestructive evaluation (NDE) of structural components. Among analytical computation, numerical simulation, and experimental studies to investigate the stress/strain field around a structural discontinuity, experiments are the most accurate in revealing the actual complex strain conditions. In this paper, a strain-sensing smart skin (S4) film sensor was used to study the strain distribution in metallic plates near different structural discontinuities. S4 is a newly developed, noncontact, full-field strain technology that utilizes the strain-sensitive photoluminescent properties of single-walled carbon nanotubes (SWCNTs). Aluminum bars in tension were studied in two cases—with a central hole and with an edge notch. In both cases, S4 film sensors measured the residual strain contours near structural discontinuities under large axial loading at room temperature. Linear elastic fracture mechanics (LEFM) was used to compute the closed-form solution of strain fields. Finite-element elastoplastic nonlinear models were also constructed and validated by using strain gauge data from the experiments. The FE analysis results were found to match the strain distribution obtained from S4 measurements. S4 technology can be usefully applied in the realms of nondestructive evaluation, experimental mechanics, and structural health monitoring.
出版年：	2019
期刊名称：	Journal of Structural Engineering
卷：	145
期：	1
页码：	1-20