Test Methods for analysis of Infusion panels (SOFIA)

Date

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Brief relate

The SOFIA project studies the behavior of curved compression-stiffened panels, typical of the aeronautical industry. The novelty of the project lies in the manufacturing process of the stiffened panel, which is carried out using resin infusion techniques, instead of conventional gluing (or co-gluing) of the stiffeners to the skin.

Three entities participate in the project: AICIA (University of Seville), ALESTIS, APPLUS, with the tasks entrusted to each participant being those indicated below:

  • AICIA (University of Seville) will carry out level 2 tests, on configuration details, to characterize the new admissibles of the different panel failure mechanisms.
  • ALESTIS will carry out numerical modeling of the tests and will manufacture the necessary tools for the tests. He is the project coordinator.
  • APPLUS will carry out the level 3 test of the complete compression panel.

Sequentially, in the project, level 2 tests will be carried out to obtain certain allowable values ​​for different failure mechanisms, and subsequently, a complete panel compression test will be carried out.

The admissibles obtained in the level 2 tests will be used, together with numerical modeling, to try to predict the failure of the panel during the level 3 test.

Trials that are scheduled to be carried out include:

  • GIC tests to determine the critical energy of the potential detachment of the stiffener and skin. When manufacturing occurs by resin infusion, there is no, from a formal point of view, an adhesive interface between both components, so this admissible interface is not preliminarily characterized.
  • “Unfolding” tests , to determine the failure load in the radius of agreement of the stiffener.
  • Compression tests after impact , which allow having an admissible compression in the panel with certain damage (typically delamination), after suffering an impact normal to its surface.
  • 7-point bending tests , which allow us to reproduce (in a certain way) the deformed configuration that the panel finds under compression and after suffering dents generated by the instability caused by compression.