Investigation of the effect of matrix volume fraction on fiber stress distribution in polypropylene fiber composite using a simulation method

The study of the fracture behavior of polypropylene/glass fiber (PP/GF) composites can be an interesting subject for many investigators. Since glass fiber and polypropylene have different elastic moduli, a complex stress distribution will be developed when the composite body is loaded uniaxially in the direction of fibers. Thus, the prediction of stress distribution by using a simulation method can be helpful for more understanding of the true reasons of fracture of polymer composites. This research is focused on the effect of fiber–matrix interaction on stress distribution along fibers. For this purpose, finite element method was performed. The results of analytical method show that stress distribution along fiber length strongly depends on matrix volume fraction. In fact, increasing matrix volume fraction causes to change variation of stress distribution along fiber length from trapezoidal to parabolic. Looking at in more details on matrix placed near fiber tip indicates that the stress intensity is higher than that of other zones and it leads the matrix to crazing. The simulated results were confirmed by SEM micrographs taken from the polished surface of polypropylene/glass fiber composite, which is loaded under tensile test.