On the Determination of Fiber Strengths by In-Situ Fiber Strength Testing

Abstract

A method is described and experimental results given which demonstrate the feasibility of determining fiber strengths at short gage lengths by monitoring the fiber failure process during the embedded single-fiber fragmentation test. A computerized weakest link fiber model was used to perform data analysis, without making assumptions about the statistical nature of the flaw distributions. Fiber strength data at short gage lengths can be directly obtained by this technique without the necessity for extrapolation from longer specimens. A dependence on specimen fabrication technique was found, which demonstrates the necessity of careful control of fiber prestrain. Specially fabricated strain-free specimens tested by this method, the in-situ fiber strength test (ISFS), generated length-strength data that were in close agreement with conventional tension test results.