Testing the methodology at Empa

The draft validation protocols are being employed on a static panel test at Empa, Switzerland.
Panel test
The validation protocols were deployed on a singly curved skin-stringer-frame assembly in a compression test, using DIC to measure deformation under various load cases and to compare the results to FE-simulations. The panel is part of the fuselage skin from an A340 aircraft.
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The Airbus panel in the compression test machine in front of the DIC system.
Panel preparation

The Airbus panel was brought  to a convenient size of about 1 m2 by waterjet cutting. The ends were potted to allow force introduction through the platen of the testing machine. The geometry of the panel was controlled in order to update the numerical model for simulation. Finally, a self-adhesive speckle pattern was glued onto the outside of the test panel for DIC deformation measurements.

    

Test panel after cutting (left). Two curved frames run across the panel, while five stringers will take compressive load. Potting of the panel ends (right).

   

Check of the geometrical details (left) and application of the speckle pattern (right).