Statistical aspects of the failure of organic-fiber-reinforced plastics

Effect of Longitudinal Splitting on Tensile Strength of Unidirectional Aramid Fiber Reinforced Plastics

“…Nevertheless, if j8 values were determined by the averaging results of testing of a number of different yarns (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) via the same method, they were found to be similar for Terlon, Armos and SVM fibers. With determination of j8 via dependence of the yam strength on gauge length, j8 was found to be in the range of 12.0 to 13.0 for SVM [23], 13.5 for Armos [24] and 12.0 for Terlon fibers [7]. Since the difference in (3 values for different types of aramid fibers was insignificant, equality of the monofilament strength at gauge length Lf should provide equal composite strength.…”

“…However, there are two methods of finding the Weibull j8 parameter. The first is by determination of the fiber strength distribution at some fixed gauge length [21,22], and the second is by the determination of dependence of yam (or monofilament) strength on the gauge length [23]. Determined by these methods the jf3 values do not coincide.…”

“…Determined by these methods the jf3 values do not coincide. For SVM fibers j8 was estimated as 8 [21] and 12 [23] for the first and the second methods respectively. Nevertheless, if j8 values were determined by the averaging results of testing of a number of different yarns (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) via the same method, they were found to be similar for Terlon, Armos and SVM fibers.…”