Investigation of manufacturing defects in 3D-printed CFRP using laser ultrasonic testing and x-ray micro-computed tomography

June 12, 2021

Sang-Yeon Cho (1), Jung-Ryul Lee (1)
Functional Composites and Structures, 3, Issue 2, June 2021. DOI: 10.1088/2631-6331/ac034d


3D printed CFRP; manufacturing defects; laser ultrasonic testing; x-ray micro-computed tomography


3D-printed carbon fiber reinforced plastic (CFRP) composites have attracted significant attention due to their design flexibility and low manufacturing cost. However, 3D-printed CFRP contains inherent defects that occur during the manufacturing process. As the manufacturing defects are likely to degrade the mechanical performance of the 3D-printed CFRP, these defects require extensive investigation. Typically, x-ray micro-computed tomography (micro-CT) is used to detect manufacturing defects, but as micro-CT cannot be applied to large structures, the laser ultrasonic testing (LUT) method has been proposed. In this study, two specimens with different stacking sequences were manufactured using a continuous fiber 3D printer. The two specimens were then inspected using LUT and micro-CT. The manufacturing defects were successfully visualized using LUT, and similar defects were detected in the micro-CT inspection results. The size, location, and shape of the detected defects were evaluated by comparing the LUT and micro-CT inspection results. Consequently, the LUT method showed a performance comparable to that of micro-CT for detecting the manufacturing defects of 3D-printed CFRP. Since the LUT is capable of inspecting large scale 3D-printed composites, it will be absolutely advantageous in real world applications.

How Our Software Was Used

Dragonfly was used to obtain cross-sectional images by slicing the 3D digital model.

Author Affiliation

(1) Department of Aerospace Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.

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