Hamid SadAbadi - Graduate student, Faculty of Mechanical Engineering K.N.Toosi University of Technology-Tehran-Iran
Meysam Tatari - Graduate student, Faculty of Mechanical Engineering Tarbiat Moddares University-Tehran-Iran

Calculation of fiber orientation distribution is the reference standard for determining the numerous physical and mechanical properties of injection molded short fiber (SF) reinforced thermoplastics. On the other hand, most of properties of these composites depend ontheir fiber orientation pattern that can be represented by tensorial notation, aij. This study is focused on calculation of fiber-orientation tensor of an injectionmolded Short Glass Fiber reinforced polystyrene (SGFPS) composite part, which shaped as rectangular plate in a specific point by using numerical method via a software package. In this paper, the effect of some injection molding process parameters includes, injecting flow rate, mold wall temperature and packing pressure on changes of fiber orientation of this specimen is simulated. The simulation shows that how these parameters can affect on the fiber orientation pattern of the part through its thickness in that mentioned point. The results indicate injecting flow rate has the most affect on the fiber orientation and packing pressure almost has no effect on it. To have confidence about the software results, at the first step, the results of the software are validated by comparing them with their published experimental data in one case. Note that, the subject matter that is more important than the absolute value of orientation of fibers in every condition is the relative changes of this orientation in every case that is the base purpose of this study.

Fiber orientation tensor، injection molding، short glass fiber، polystyrene، composite material