Abstract
According to the recent remarkable development of bend-insensitive optical fibers, silica optical fibers are beginning to be used with small bending radii for many applications. However the radical decrease of the bending radius may cause delayed failure of the fibers when they are used in harsh environment, because the conventional theories to estimate the mechanical reliability of the bent portion are not applicable to such a case. Though one of the authors has driven an enhanced equation applicable to the fibers at high temperature and/or high humidity, calculations with the equation are not so easy because numerical integration must be done. We now propose another simpler equation that we have driven from commonly-used conventional equations. Calculations for specific conditions were carried out with the parameters extracted from an empirical formula in other paper. By comparing the calculation result with that of the former precise equation, the calculation error was found to be sufficiently small.
