EXPLORATION AND EVALUATION OF NEW GLASSES IN FIBER FORM
Final rept. 15 Nov 1961-25 Nov 1962
SOLAR TURBINES INTERNATIONAL SAN DIEGO CA
Pagination or Media Count:
The length effect on fiber strength was studied for E-glass and 994 glass fibers. These fibers were primarily from strands. Tensile test results confirmed the linear log strength-log length relationship previously established and that fiber strength increases with decreasing length. At short fiber lengths below 0.5 cm, the strength-length curve showed a change in slope due to the presence of mixed flaw populations, which were indicated in bi-modal failure distributions in the vicinity of the slope change. This change in slope was not anticipated in an earlier concept developed for failure prediction on the basis of the length effect. A tentative revised model is suggested but must await confirmation by experiments with controlled fiber damage. Some comparative tests on strand strength showed a strength reversal with decreasing test length. The reversal could be related to the effect of fiber collimation. Comparison of fiber properties of the different glasses on the basis of strength, weight, Youngs modulus, surface damage, and fiber length showed that 994 fibers are superior to E-glass by a factor of approximately 1.7 for longer fibers.
- Refractory Fibers