Civil Engineering Seminar: Jordan Raney

Description

The Department of Civil Engineering is pleased to welcome Dr. Jordan Raney, an assistant professor of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania, for a seminar titled "3D Printing Multifunctional Fibrous Composites with Controlled Microstructure."

Abstract:

The internal structural features of material systems greatly affect their macroscopic mechanical properties. For example, natural structural materials such as wood possess highly heterogeneous mesoscale architectures, with hierarchical structure, spatially-varying fiber alignment, non-uniform density, and graded porosity. These features are the result of localized structural and compositional optimization, producing maximal bulk mechanical properties that greatly exceed those of the constituent materials as well as fascinating stimuli-responsiveness. Researchers have long sought the ability to produce synthetic composites of comparable microstructural complexity. Additive manufacturing techniques have begun to enable more nuanced control of the internal structure of engineering materials, but many challenges remain, including notable process-intrinsic limits to the palette of printable materials. Here, direct-write 3D printing is used to print short fiber composites with controlled fiber orientation, with the goal of enabling a new degree of control over their mechanical properties and responsiveness to their environment. Ink materials with fibrous fillers are developed based on epoxies, elastomers, and natural matrices, producing highly anisotropic materials during extrusion through a deposition nozzle. Using this approach, we control the fiber alignment to produce 3D-printed parts that demonstrate both enhanced damage tolerance and "embodied logic" based on instability-induced shape change.