Page 25 - MSAM-2-3

Materials Science in

Additive Manufacturing

ORIGINAL RESEARCH ARTICLE
Modeling and experimental investigation

of fiber orientation in cast and 3D-printed
cementitious composites

1
Mingyang Li , Dong Zhang , Teck Neng Wong , Ming Jen Tan , and
2
1
1
Yiwei Weng *
3
1 Singapore Centre for 3D Printing, Nanyang Technological University, Singapore
2 Sustainable and Innovation Bridge Engineering Research Centre, College of Civil Engineering,
Fuzhou University, China
3 Department of Building and Real Estate, The Hong Kong Polytechnic University, Hong Kong, China

Abstract

Fiber orientation is process-related and has significant impacts on material
performance. However, existing studies only consider the impact of individual factors
on the fiber orientation, either boundary impacts or flow field impacts. This work aims
to study fiber orientation by considering the combined impact of these two factors.
Analytical models were first constructed, which revealed that when the flow of
material is negligible, fiber orientation is impacted by the boundary conditions. When
the flow field is non-negligible, fiber orientation is affected by the direction of flow
streamlines. Specimens were then prepared using fluorescence image processing and
µ-computed tomography scanning for fiber orientation analysis. The results indicate
*Corresponding author:
Yiwei Weng that fiber orientation could be controlled by varying boundary constraints and flow
(yiwei.weng@polyu.edu.hk) fields. Mechanical results reveal that when the designed condition achieves directional-
Citation: Li M, Zhang D, Wong TN, orientated fibers, the mechanical property of specimens could be enhanced with the
et al., 2023, Modeling and applied stress direction being the same as the fiber orientation. This work provides a
experimental investigation of fiber novel insight to tailor fiber-reinforced cementitious material properties by designing
orientation in cast and 3D-printed
cementitious composites. Mater Sci the boundary constraints and flow fields in the cast and printing processes.
Add Manuf, 2(3): 1603.
https://doi.org/10.36922/msam.1603
Keywords: Additive manufacturing; Fiber orientation; Flow field; Boundary constraint;
Received: August 15, 2023 Mechanical property
Accepted: September 9, 2023
Published Online: September 22,
2023
Copyright: © 2023 Author(s). 1. Introduction
This is an Open Access article Fiber orientation plays a key role in the mechanical performance of fiber-reinforced
distributed under the terms of the
Creative Commons Attribution composites (FRCs). The addition of short fibers in brittle concrete matrix contributes
License, permitting distribution, and to the fiber bridging effect, which could improve the energy absorption capacity and
reproduction in any medium, which crack resistance of plain concrete . Wu and Li’s work reveals that material mechanical
[1]
[2]
provided that the original work is
properly cited. property is affected by the fiber orientation. With an increasing inclination angle, which
represents the angle between the fiber orientation and the loading force in the tensile test,
Publisher’s Note: AccScience
[3]
Publishing remains neutral with the in situ fiber strength decreases, leading to a deterioration of the fiber-bridging effect .
regard to jurisdictional claims in
published maps and institutional Fiber orientation is process-related in the material. In sprayable FRCs, fibers are
affiliations. distributed in a two-dimensional plane [4,5] . In extrudable FRCs, on the other hand,
Volume 2 Issue 3 (2023) 1 https://doi.org/10.36922/msam.1603