Abstract
A micro-interferometric technique for measuring out-of-plane thermal displacements on a scale commensurate with the dimensions of the fiber/matrix unit cell is described. A scanning micro-interferometer is used to image surface displacements of samples containing a single-pitch-based carbon fiber embedded in an epoxy matrix. The interferometer design gives the necessary resolution to detect small changes in thermal displacements in the fiber/matrix interface region. The samples were heated electrically through the fiber to create radially symmetric temperature and displacement fields. Repeatable displacement measurements were obtained on a radial line across the interface region with an accuracy of ±25 Å. A sharp expansion of the matrix surrounding the fiber was observed with each heating. Overall, the experiments demonstrate the utility of micro-interferometry for measuring submicron displacements.
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Sottos, N.R., Scott, W.R. & McCullough, R.L. Micro-interferometry for measurement of thermal displacements at fiber/matrix interfaces. Experimental Mechanics 31, 98–103 (1991). https://doi.org/10.1007/BF02327559
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DOI: https://doi.org/10.1007/BF02327559