Integrated manufacturing of REciclable multi-material COmposites for the TRANSport sector
Automated bondline thickness quantification in adhesively joined composites and metals using ultrasound
This paper presents a methodology using full waveform ultrasonic signals to quantify the adhesive dimensions of bonded laminated composites with each other and metallic panels with each other.The use of adhesively bonded joints between composite panels, metal panels, or between composites and metals are used in the aerospace and automotive industries to avoid stress concentrations due to fasteners while reducing weight. Quantifying the bond thickness allows for confidence that loading is being properly transferred. This study presents a methodology to measure bondline thickness using the data obtained from an immersion quality ultrasound scan using an out?of?tank, field?portable, utlrasonic testing (UT) scanner. Eighteen bonded coupons were fabricated using a paste?type adhesive filling a range of gaps between substrates of 0.254 and 1.27?mm. Three adhesively bonded coupon types were investigated: carbon fiber laminates, fiber glass laminates, and aluminum plates. A semiautomated algorithm is presented to quantify bondline thickness from the ultrasound data for each coupon type, generating a spatially varying 3D point cloud of adhesive thickness. Bondline measurements obtained using ultrasound are then validated over two orthogonal planes against measurements taken from x?ray computed tomography reconstructions. Results indicate a typical accuracy of 0.081?mm for bondline thickness quantification for all samples studied, with the results from the inspection of the composite coupons yielding an error of 0.078?mm, whereas the accuracy when scanning the aluminum coupons yielded an error of 0.086?mm.HighlightsField?portable, inspection station is presented for full waveform ultrasonics.Mathematical procedure to characterize adhesive bondline thickness.Results are presented for a variety of material systems and adhesive thicknesses.Results are validated against x?ray computed tomography with a typical accuracy of 0.081?mm.
» Publication Date: 30/11/2023
This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement Nº 768737
