Effect of the nonlinear stress-strain relationship on the maximum stress in silica fibers subjected to two-point bending.
We evaluate the effect of the nonlinear stress-strain relationship on the maximum curvature and maximum stress in silica fibers subjected to two-point bending. The analysis uses an assumption that this relationship, obtained experimentally for the case of uniaxial tension is also valid in the case of compression and is applicable to bending deformations as well. We show that the shift in the neutral axis due to the nonlinear stress-strain relationship has an appreciable effect on the maximum stress, while its effect on the maximum curvature is small and need not be considered. We show also that this relationship, obtained for strains not exceeding 5% cannot be applied for very large strains. Therefore we conclude that the future experimental work should include the evaluation of the nonlinear behavior of the material, both in tension and compression, for higher strains and for high strength fibers. The obtained results can be helpful in the analysis of optical silica fibers experiencing two-point bending.
Suhir
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