Abstract
This work deals with the plastic deformation of polypropylene, PAN-based carbon and Kevlar fibres at different gauge lengths and uses the Weibull model. A statistical analysis for the fibre strength and breaking strain is presented to test the experimental data relating to the fibre deformation. The mechanical parameters such as fibre strength, breaking strain and Young's modulus have been studied as a function of gauge length. It was found that both strength and breaking strain increase as fibre gauge length decreases, while the Young's modulus increases with increasing gauge length and depends on both strength and breaking strain. The output of the analysis supports the concept that the Weibull model is a good technique to specify the statistical distribution for strength and breaking strain of fibres and of suitable to investigate, is the deformation behaviour of fibrous polymeric materials in general.