Applications of the wavelet synchrosqueezed transform for ultrasonic inspections : quantifying layer height and visualizing missing extrudates in material extrusion printed samples and visualizing wrinkles in carbon fiber laminates.


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In the aerospace industry there is a push to find uses for additively manufactured components with the goal of taking advantage of the increased freedom of design that it allows. Material extrusion, specifically fused filament fabrication (FFF), is one of the most prevalent methods for additive manufacturing currently used in industry. Currently the main use of additive manufacturing in the aerospace industry is for use in rapid prototyping. To move from that to functional use, additively manufactured components need to be inspectable. This thesis aims to improve existing inspection methods for material extrusion printed components by introducing the use of the wavelet synchrosqueezed transform (WSST) in the analysis of ultrasonic testing (UT) inspection data. The proposed method uses the WSST to quantify layer height and visualize missing extrudate. The method for quantifying layer height was extended to the visualization of wrinkles in carbon fiber laminates which are commonly used in the aerospace industry.