COMMITTEE CHAIR: Dr. Jaejong Park

TITLE: OPTIMIZATION OF CONTINUOUS CARBON FIBER REINFORCEMENT STRATEGIES IN 3D-PRINTED ONYX COMPOSITES

ABSTRACT: Continuous fiber reinforcement in Fused Deposition Modeling allows the production of composite parts with improved strength-to-weight ratios compared to standard polymer prints. However, overall performance depends on reinforcement strategy, layer height, print orientation, and material usage, which creates challenges for selecting efficient printing parameters. This study investigates the mechanical behavior and cost efficiency of Onyx specimens produced on the Markforged X7 platform. The work is divided into two phases. The first phase examines how layer height influences tensile strength by printing and testing specimens at 0.1 millimeters, 0.125 millimeters, and 0.2 millimeters. These tests establish a baseline that helps identify printing settings suitable for continuous fiber reinforcement. The second phase evaluates the effects of five reinforcement strategies, including Onyx only, unidirectional fiber, isotropic fiber, concentric fiber, and fiber placed only in the gauge section. All reinforced specimens are printed in the horizontal orientation with a fiber layer height of 0.125 millimeters. Tensile testing using ASTM D638 Type I specimens and three-point bending tests following ASTM D7264 Procedure A are used to measure strength, stiffness, and failure behavior. Print time, material usage, and estimated cost are recorded for each configuration to evaluate how reinforcement placement and printing parameters influence both performance and overall efficiency. The goal of this work is to develop a practical framework that helps engineers and designers select reinforcement strategies and printing parameters that balance mechanical performance, print time, and total material cost. This approach supports a more efficient use of continuous fiber FDM in engineering design and prototype-to-production applications.

Keywords: Continuous fiber reinforcement, FDM, composite optimization, 3D printing, tensile strength, flexural strength, Markforged X7

Location Online:

Zoom Link: https://pvpanther.zoom.us/j/97821508650?pwd=BbWJkNEvmcQXIcSzSfC1vup9E044rn.1

Meeting ID: 978 2150 8650

Passcode: 485067