- since 1996 -
|NDT.net Issue - 2018-03 - NEWS |
|The company IFC Composite GmbH fabricates
more than 1000 glass fiber reinforced leaf springs
per day for the minivans Mercedes Sprinter and
Volkswagen Crafter. Besides of destructive testing
there is a need for non-destructive testing for
production surveillance. The approximate size of
the leaf springs is 1400 mm x 70mm x 30 mm.
Unidirectional glasfiber prepregs are used. The
complete volume of the leaf spring is to be tested
Here the prototype of a test system for this purpose
is described, see figure 1.
Figure 1: Photograph of the Microwave-Based NDT System for GFRP Leaf Springs.
Figure 2: Microwave Scans of Leaf Springs with Artificial Defects.
a) Tranvsers Bore Holes b) Grooves. c) Metal Filament. d) Plastic Foil
Figure 2a shows the C-scan of a leaf spring with transversal bore holes on half height, i.e. 15 mm from lower side and top side. They are recognizable down to diameters of 1 mm.
Figure 2b shows indications of grooves which extend over the whole width of the leaf spring. They are recognizable down to 0.5 mm depth. Figure 2c shows the C-scan of a leaf spring with an oblique metal filament of 0.25 mm diameter at the bottom, i.e. at the receiver side of the microwave modul.
Figure 2d shows the indication of a plastic foil of 0.6 mm thickness. All these artificial defects are clearly recognizable.
This application note shows an example for the use of microwave-based non-destructive testing in a production line. We would like to answer your questions regarding avaible microwave-based measurement and test equipment which can also be made customer-specific and application-specific as well as regarding further use of microwave-based non-destructive testing.