Non-destructive evaluation of dissimilar material joints

Smagulova, Damira; Kaunas University of Technology; Lithuania

Smagulova, D.; Kaunas University of Technology; Lithuania
Jasiuniene, E.; Kaunas University of Technology; Lithuania

ID: ECNDT-0593-2018
Download: PDF
Session: PAUT & TFM 1
Room: G2
Date: 2018-06-11
Time: 14:10 - 14:30

The aim of this research was to find the most suitable and effective ultrasonic non-destructive technique that would enable to find defects in dissimilar material joints made of steel and GFRP.

By analyzing ultrasonic wave propagation characteristics through dissimilar joints several ultrasonic methods and transducer types were investigated using modeling and experimentally. Firstly the sample of steel and GFRP was designed in CIVA software where different solutions were used to compare the results of investigations of dissimilar material joint. It was determined that steel is 3 time less attenuating material than GFRP according to results of ultrasonic fields investigation and attenuation influence in steel and composite. Different types of transducers were applied for delamination detection between steel and GFRP. Phased array transducers were selected as the most suitable due to ability of steering of multiple elements, focusing and covering large area of the sample avoiding mechanical scanning. As a result of CIVA modeling it was determined that the amplitude difference of reflection from sample interface and sample delamination is very small what proves the complexity to detect the defects in experimental part. Comparing amplitude values of reflections from delaminations using different frequencies of phased array transducers and taking into account attenuation it was determined that the most suitable frequency to detect the defects in such sample is 3,5 MHz and 5 MHz phased array transducers.

In experimental part the Omniscan measurement system as well as phased array transducers were used for the inspection. All the artificial delaminations as well as their dimensions and depths were determined. As a result of this research, the best configuration for the delamination detection in dissimilar steel and GFRP sample was found.