Abstract
In this paper, distributions of tensile and compressive strength of PBO fibers were investigated in tensile test and compression test. Two types of PBO fibers were used in the experiment. One is conventional type of fiber. Another is high modulus type of fiber, and its crystal orientation is higher than conventional type of the fiber. Weibull analysis was performed to compare distribution of tensile strength and compressive strength. It was found that tensile strength and compressive strength of each type PBO fibers were well fitted the Weibull distribution function with 2 parameters regardless of degree of crystallization. Then, in tensile strength, shape parameter of HM type PBO fiber was lower than that of AS type PBO fiber. Also, in compressive strength, shape parameter of HM type PBO fiber was a little higher than that of AS type PBO fiber.
