Fabrication of artificial defects in aircraft components for nondestructive testing using 3D printing

• Main Author: Chan, Marcus Jia Jun
• Other Authors: Lin Rongming
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Aeronautical engineering
• Online Access: http://hdl.handle.net/10356/77487
• Institution: Nanyang Technological University

This report encompasses the suitability of nondestructive testing (NDT) methods on additive manufactured (AM) components in the aerospace industry. To understand the variation in results of eddy current testing, a suitable aerospace reference standard was referenced and fabricated using AM. The bolt hole and surface notch reference standard drawings were utilized. After fabrication of the AM reference standard for eddy current testing, a general visual inspection was being performed to identify anomalies in the constructed defects, or slots. It was found that the original defect specifications, or slot widths, were unable to meet the requirements due to technological limitations of the AM printing machine. Material fusing was prominent to a certain extent. Eddy current tests were then being performed using various types of probes. It was found that all eddy current probes and defects were able to demonstrate an indication on the impedance plane. This result therefore deduced the suitability of performing eddy current testing on AM joints in the future. Additionally, using a surface notch reference standard, the signal could be found with some difficulty as a result of its surface finish. All notches that were fabricated were found to meet the requirements of the intended design, but during testing it was found that the notches nearest to the edge cannot be used. An Ultrasonic C-scan was also being performed to understand correctly the topography provided in the results. It was found that despite being able to correctly measure the component’s depth, the topography was found to be distorted due to a combination of beam spread and machine measurement errors. Lastly, due to the limitations and cost of this project, several recommendations and improvements have been identified. A separate eddy current computer simulation was performed, which demonstrated a topographical and graphical representation of the signal. The results provide some insight into potential cost and design improvements, which would aid in the future design work of NDT of AM components.