Expert Lecture Spotlight | Prof. R. Byron Pipes
Rheology of Carbon Fiber Thermoplastic Polymer Composites
For over three decades, Prof. R. Byron Pipes has led pioneering work on the rheological behavior of fiber-reinforced thermoplastic composites—and this lecture presents a comprehensive journey through these advancements.
Key highlights include:
Elongational Viscosity of Discontinuous Fiber Systems
Initiated by the need to understand stretch-forming forces in impregnated, stretch-broken fiber tows, this research extended Batchelor’s micromechanics theory to temperature-dependent and shear-thinning polymers.
Full Viscosity Tensor Development
Beyond axial viscosity, Prof. Pipes’ team derived models for all components of the viscosity tensor—including three shear and two additional elongational viscosities—accounting for hyper-concentrated fiber systems that go far beyond dilute-suspension assumptions.
Prepreg Platelet Flow and Consolidation Modeling
Models were adapted for planar reinforcing geometries in prepreg platelet systems, capturing the early consolidation stages that define fiber orientation and geometry before molding. This laid the groundwork for simulating anisotropic molding flows driven by evolving viscosity tensors.
Validation and Application
Simulations were validated against both prepreg platelet and conventional sheet molding systems, offering practical pathways to optimize manufacturing.
Recent Advances
More recent work explores viscoelastic bending in collimated fiber systems, with implications for:
- Sheet forming
- Extrudate rheology in additive manufacturing
Looking Ahead
The lecture concludes with reflections on the next frontiers in rheological modeling of advanced composites, including new challenges in manufacturing science, material design, and digital process control.
Watch the full lecture on cdmHUB’s YouTube channel as part of the Global Composites Expert Webinar Series.
