Fabrication of defects in 3D printed materials for ultrasonic analysis

Ultrasonic testing (UT) is widely used to detect the presence of defects typically in denser materials such as metals. Its application to 3D printed plastics presents unique challenges due to high attenuation of ultrasound in such materials. This project investigates the feasibility of UT on Polylac...

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Bibliographic Details
Main Author: Sim, Qin Li
Other Authors: Chai Gin Boay
Format: Final Year Project (FYP)
Language:English
Published: Nanyang Technological University 2024
Subjects:
Online Access:https://hdl.handle.net/10356/177467
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author Sim, Qin Li
author2 Chai Gin Boay
author_facet Chai Gin Boay
Sim, Qin Li
author_sort Sim, Qin Li
collection NTU
description Ultrasonic testing (UT) is widely used to detect the presence of defects typically in denser materials such as metals. Its application to 3D printed plastics presents unique challenges due to high attenuation of ultrasound in such materials. This project investigates the feasibility of UT on Polylactic Acid (PLA) specimens fabricated via Fused Deposition Modelling (FDM) and explores the effects of different factors such as probe frequency and defect characteristics on UT dimensional accuracy. Straight-beam UT probes of frequencies 0.5 MHz to 20 MHz were used alongside an automatic ultrasonic C-scan machine to obtain C-scan and A-scan displays of embedded defects within the printed specimens. The six experiments conducted highlighted the importance of having a small transducer area relative to the size of the defect. High probe frequencies could size defects more accurately though the signal-to-noise ratio would be lower, and scans conducted from top surfaces of specimens with respect to the build orientation faced problems in the presence of overhanging material within the specimen. Despite advancements, challenges persist in achieving reproducible and accurate UT results in 3D printed specimens, attributed to the high ultrasound attenuation which is exacerbated by low infill density.
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spelling ntu-10356/1774672024-06-01T16:51:44Z Fabrication of defects in 3D printed materials for ultrasonic analysis Sim, Qin Li Chai Gin Boay School of Mechanical and Aerospace Engineering Brian Stephen Wong MGBCHAI@ntu.edu.sg Engineering Ultrasonic testing 3D printing Ultrasonic testing (UT) is widely used to detect the presence of defects typically in denser materials such as metals. Its application to 3D printed plastics presents unique challenges due to high attenuation of ultrasound in such materials. This project investigates the feasibility of UT on Polylactic Acid (PLA) specimens fabricated via Fused Deposition Modelling (FDM) and explores the effects of different factors such as probe frequency and defect characteristics on UT dimensional accuracy. Straight-beam UT probes of frequencies 0.5 MHz to 20 MHz were used alongside an automatic ultrasonic C-scan machine to obtain C-scan and A-scan displays of embedded defects within the printed specimens. The six experiments conducted highlighted the importance of having a small transducer area relative to the size of the defect. High probe frequencies could size defects more accurately though the signal-to-noise ratio would be lower, and scans conducted from top surfaces of specimens with respect to the build orientation faced problems in the presence of overhanging material within the specimen. Despite advancements, challenges persist in achieving reproducible and accurate UT results in 3D printed specimens, attributed to the high ultrasound attenuation which is exacerbated by low infill density. Bachelor's degree 2024-05-29T01:11:08Z 2024-05-29T01:11:08Z 2024 Final Year Project (FYP) Sim, Q. L. (2024). Fabrication of defects in 3D printed materials for ultrasonic analysis. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/177467 https://hdl.handle.net/10356/177467 en B309 application/pdf Nanyang Technological University
spellingShingle Engineering
Ultrasonic testing
3D printing
Sim, Qin Li
Fabrication of defects in 3D printed materials for ultrasonic analysis
title Fabrication of defects in 3D printed materials for ultrasonic analysis
title_full Fabrication of defects in 3D printed materials for ultrasonic analysis
title_fullStr Fabrication of defects in 3D printed materials for ultrasonic analysis
title_full_unstemmed Fabrication of defects in 3D printed materials for ultrasonic analysis
title_short Fabrication of defects in 3D printed materials for ultrasonic analysis
title_sort fabrication of defects in 3d printed materials for ultrasonic analysis
topic Engineering
Ultrasonic testing
3D printing
url https://hdl.handle.net/10356/177467
work_keys_str_mv AT simqinli fabricationofdefectsin3dprintedmaterialsforultrasonicanalysis