Fiber Orientation and Length Modeling: Concepts Behind the Calculations

Autodesk® Simulation Moldflow® Insight software offers the ability to predict the orientation of fibers in a molded part, and it has recently added a capability for predicting fiber length attrition. This information is useful for both short- and long-fiber molding compounds. But what lies behind these predictions? This class looks at the concepts behind the modeling of fiber orientation and fiber length. There are some equations, but the emphasis is on understanding the ideas behind each model. We start with the original fiber orientation model of Jeffery (from 1923!) and work up to the latest models for long-fiber molding compounds. We also look at the newest addition to this area—a model for process-induced changes in fiber length. The overall goal is to help attendees make smart choices about which orientation model to use and to understand how to choose the material parameters in each model.