Probabilistic model for structural mechanics of fiber bundle and its application to PBO fiber

Abstract

The stress-strain relationship of single fiber and fiber bundle based on the different strain distribution functions of single fiber, including rectangular distribution, normal distribution and Weibull distribution, was studied. Strain distribution of Poly-p-phenylene benzobisoxazole (PBO) single fiber was measured, and the stress-strain curve of PBO fiber bundle can be deduced from the different strain distribution functions of single fiber. The results showed that normal distribution was closer to the measured strain distribution of PBO single fiber than rectangular distribution, and the stress and strain values of PBO fiber bundle estimated by the normal distribution were closer to the measured stress and strain values of PBO fiber bundle. In addition, the stress and strain values of PBO fiber bundle estimated by Weibull distribution were between those of rectangular distribution and normal distribution. In a word, the normal distribution can be effectively used to predict the fracture process of PBO fiber bundle.