Probabilistic Theories of Time Dependent Failure of Fiber Bundles

This paper summarizes recent advances in modeling the static and time dependent failure of fiber bundles. The fibers are assumed to exhibit statistical variations in tensile strength which may be influenced by the fiber load histories. The bundle load is shared among the surviving fibers at any given time according to a load sharing rule that takes into account statistical variations in the geometric and mechanical properties of the individual fibers. On a force per fiber basis, the static and fatigue strength of a bundle is less than the average strength of the fibers. The strength loss increases with increased variability in fiber strength, time-to-failure and load sharing. The variability in bundle strength however decreases with an increase in the number of fibers in the bundle. The paper gives many strength prediction relationships that will have use in the design of high strength cables and lines.