Moiré interferometry for thermal expansion of composites

Autor:	D. E. Bowles, D. R. Tenney, Carl T. Herakovich, Daniel Post
Rok vydání:	1981
Předmět:	Diffraction Materials science business.industry Mechanical Engineering Aerospace Engineering Atmospheric temperature range Grating Standard deviation Thermal expansion Reflection (mathematics) Optics Interference (communication) Mechanics of Materials Thermal Composite material business
Zdroj:	Experimental Mechanics. 21:441-447
ISSN:	1741-2765 0014-4851
Popis:	Moire interferometry by reflection is described and demonstrated for the case of a real reference grating of 1200 lines/mm. Extraneous beams can be displaced and stopped by using a wedge-shaped air gap between reference and specimen gratings. Double-order dominance, the use of diffraction sequences for reflection, the isolation of preferred sequences, and the use of two-beam interference are discussed. Experimental accuracy is enhanced significantly by using several data points to establish displacements along a line, and random errors characterized by one standard deviation can be as small as one microstrain. The method is well adapted to thermal environments, coefficients of thermal expansion of selected graphite-epoxy laminates being determined in the temperature range of 297-422 K. Very good precision was achieved for a wide range of thermal expansion coefficients, from approximately zero to 27 microstrains/K.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7991a2370c23b5ae4d84826acea37d27 https://doi.org/10.1007/bf02327415 Zobrazit plný text záznamu Full text from SpringerLink