The Strength of Glass Fibres. Part II. The Effect of Heat Treatment on Strength

JSGT 1944 V28 T388-T405

An apparatus is described for the rapid determination of the breaking strain of glass fibres. The effect of heat treatment on the strength is shown to follow the changes in the elastic moduli recorded in Part I. The strength is reduced to about 70% of the original value by heating to 400° for 30 minutes, and to about 50% by heating to 520° for the same period. Distribution curves of the breaking strains are compatible with a random distribution of "flaws," which increase in number when the fibres are heated.

J. B. Murgatroyd