Young's modulus prediction of long fiber reinforced thermoplastics

The aim of this paper is to provide analytical models able to predict the elastic properties of long fiber reinforced thermoplastics (LFT) in dependence of microstructural parameters such as the fiber volume content (vf), the fiber orientation distribution (FOD) and the fiber length distribution (FLD). The analytical predictions are compared to the experimental stiffness values from tensile tests on the composite material showing a good agreement. The FLD in terms of the probability density distribution as function of the fiber aspect ratio has been computed by an automated fiber separation and image analysis tool. On the other hand, the FOD in terms of the probability density distribution as function of fiber in-plane orientation was identified by using an image correlation procedure based on computer tomography scans of characteristic LFT specimens. Our analysis shows a good performance to predict Young's modulus of LFT due to incorporation of the FOD as well as the FLD into the calculations.