| The material flow in short-fiber-reinforced composite material during compression molding of a plate-rib type geometry was investigated via experimental and numerical studies using sheet molding compound (SMC). Previous studies illustrated that the disruptive material flow, resulting from the interaction between the reinforcing fibers and the resin during molding of rib-plate type geometry, creates an area that is richer in resin near the surface opposite to the location of the rib. Consequently, this resin rich area exhibits different thermophysical properties, and this difference results in a surface defect called "sink mark" after polymerization and cooling. Therefore, the ability to understand and model the complex flow mechanism in the short-fiber-reinforced composite materials for manufacturing rib-plate type geometries was critical in preventing such a defect.;The reinforcing fibers were considered to be the source of anisotropic material flow. The amount and the length of the reinforcing fibers in relation to material anisotropy were investigated. The influences of the interfacial friction, between SMC charge and the mold surfaces, and the mold closing speed on the flow were also examined. A measurement procedure which transforms this empirical information to a numerical structure was required for a valid mathematical model. A computer model which incorporates the results of measurement was constructed, and the validation was performed by comparing the results of computer simulation with the molding experiments. |
