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IX.—On the Measurement of Stress by Thermal Methods, with an Account of some Experiments on the Influence of Stress on the Thermal Expansion of Metals

Published online by Cambridge University Press:  06 July 2012

E. G. Coker
Affiliation:
Assistant Professor of Civil Engineering, M'Gill University, Montreal

Extract

In the determination of the effects of stress upon different materials, the investigator has several methods of attack open to him, each of which has its own particular advantages. In the great majority of cases the material under investigation obeys the generalised Hooke's law, and the effects of a stress are therefore most easily followed and measured by observations of the strains produced. The strains being usually exceedingly minute, it is necessary to magnify them sufficiently to allow of accurate measurement. To this end many instruments have been devised for measuring the strains obtained by the action of different stresses, and in fact the great majority of our experimental knowledge has been obtained in this way. The application of polarised light to the determination of stress was first suggested by Brewster, and he applied it to many problems, particularly the determination of the neutral axis of a glass beam. Neumann, with a full knowledge of the work of Brewster, developed a theory of the analysis of strain by polarised light, and Maxwell also independently developed a theory. A third method, which has assumed great prominence in recent years, is the microscopic examination of metals under stress, as developed by Ewing, and Rosenhain, and others.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1906

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References

page 229 note * Trans. R.S.E., vol. iii.

page 229 note † Abhandlungen der k. Akademie der Wissenschaften zu Berlin, 1841.

page 229 note ‡ “On the Equilibrium of Elastic Solids,” Trans. R.S.E., 1853.

page 229 note ∥ “On the Crystalline Structure of Metals,” Trans. R.S., 1900.

page 229 note § Poggendorff's Annalen, Bd. xx., 1830.

page 230 note * “Mémoire sur le calcul des actions moleculaires développées par les changements de température dans le corps solides,”—Memoires… par divers savans, vol. v., 1838.

page 230 note † “On the Dynamical Theory of Heat,” Trans. R.S.E., 1851.

page 230 note ‡ “On some Thermo-Dynamical Properties of Solids,” Trans. R.S., 1853.

page 230 note § “Untersuchung über die bei voluniveränderung fester körper entstehenden wärmephänomene, sowie derein verhaltniss zu dabei geleisteten mechanischen arbeit,” Pogg. Annal., vol. cxiv., 1861, and “Quantitative bestimmung der bei volumveränderung der metalle enstehenden warmephänomene und die mechanischen wärmeaequivalents, unabhängig von der inneren arbeit des metalls,” Pogg. Annal., vol. cxxvi., 1865.

page 231 note * “Thermo-Electric Measurement of Stress,” Trans. Amer. Soc. C.E., 1902.

page 232 note * “On some Thermo-Dynamic Properties of Solids,” Phil. Trans., 1859.

page 234 note * “On a flexible Joint for securing Thermometer and like Stems and Tubes,” E. G. Coker, Physical Review, 1903.

page 241 note * Loc. cit., ante.

page 248 note * “On the Flexure of Heavy Beams subjected to Continuous Systems of Load,” Quart. Jour. Math., 1889.

page 249 note † “A New Extensometer,” Trans. Roy. Soc. Canada, 1901