Title: Modeling of Extrusion-Based 3D Printing of Cementitious Materials

Author(s): Narayanan Neithalath, Gaurav Sant, Pu Yang, and Sooraj Nair

Publication: Web Session

Volume: ws_S19_Neithalath.pdf

Issue:

Appears on pages(s):

Keywords:

DOI:

Date: 3/24/2019

Abstract:
This presentation aims to model the extrusion-based 3D printing process cementitious mixture to evaluate the linkage between particle scale processes and extrusion process. An appropriate rheological model is used to model extrusion by the Discrete Element Method (DEM), and extract the relevant parameters. They are then implemented in a scaled-down extrusion printing model to determine the influence of particle-scale effects on extrusion force. The DEM model can capture the differences in extrusion load-displacement responses similar to the experiments. An analytical model is also used to describe the extrusion process. A geometric ratio is defined to bring out the effects of the nozzle-die geometry on the extrusion response. The models successfully predict the extrusion yield stress, the shaping and die wall shear stresses, and the length of the dead zone. Refinements to the model based on extracted parameters are also discussed, to lead to realistic relationships between the material design and extrusion in field scale 3D printing.