Kechagia, Ioanna

2022-06-01T11:06:25Z

https://repository.ihu.edu.gr//xmlui/handle/11544/29931

3d printing

CFF

Evaluating the effect of fiber position and orientation on flexural properties of 3D printed continuous carbon fiber reinforced nylon composite.

1106200004

2022-03

free

School of Science and Technology, MSc in Strategic Product Design

This dissertation was written as part of the MSc in Strategic Product Design at the International Hellenic University. The 3d printing technology mainly used for rapid prototyping is a revolutionary technology over the last years. 3d printing, also referred to as Additive Manufacturing (AM), is a process of fabricating polymer, metallic, ceramic materials with complex geometries. There have been several attempts to address the poor mechanical characteristics of 3D printed parts. One option is to add fiber reinforcement to increase structural strength. The composite's reinforcement might be either continuous or discontinuous short fibers. The mechanical performance of discontinuous fiber is lower than that of continuous fiber [1]. In this scenario, continuous carbon fiber with ultrahigh mechanical features is chosen. In this study, samples from nylon and carbon fibers were printed using Markforged Two printer through Continuous fiber fabrication. The effect of fiber volume fraction, fiber orientation, and fiber distribution and placement on the flexural properties were investigated using three-point flexural testing. The flexural mechanical characteristics of composites are crucial factors to evaluate in structural applications. The study aims to discover the best combination of fiber distribution and orientation with as few reliable experiments as possible that have better mechanical properties in bending. The present study is prepared as follows. First is provided a brief overview of published review articles focused on flexural test in 3d printing composite samples (nylon or onyx with carbon fiber) and a comparison of mechanical properties. Next, the Markforged 3d printer was presented, and analyzed the experimental methodology of 3d printing and flexural tests. Finally, the experimental results are evaluated and key results are highlighted concerning the effect of different process parameters. According to a literature review [2], flexural tests demonstrate that concentric pattern performs better in bending than in tension. Therefore, saving time and carbon fiber material specimens were printed specimens in top-bottom, central, and sandwich deposition patterns with fibers oriented concentrically with 2 rings (concentric pattern). I focus on iv categories with better mechanical properties to change the orientation and fiber fill type (for concentric to isotropic and hybrid). Conclusions and suggestions for future research of this work are outlined.

Karalekas, Dimitrios

ihu