Final Report Summary - DATON (Innovative fatigue and damage tolerance methods for the application of new structural concepts)
The project was structured into five work packages (WPs), as follows:
- WP1: Definition of the scope of the project
- WP2: Numerical tools and modelling
- WP3: Manufacturing and testing
- WP4: Validation
- WP5: Improved damage tolerance designs and methodology.
From the experimental point of view, nearly 120 stiffened panels, manufactured from three different aluminium alloys, namely 6056-T6 (to be tested as welded), 6056-T4 welded and then aged to -T6, and 2024-T3, have been tested.
From the methodological point of view, fracture-mechanical methods have to include primarily the ability to take this influence into account. It could be shown that different methods of calculation (finite element methods, boundary element methods, quasi-analytical methods, etc.) all yield good results. Apart from the influence of the residual stresses, the question of anti bending guides and their representation in the models was found to be essential, too.
The definition of critical parameters for the optimum design of integrally stiffened metallic structures which reflects the experiences made by the partners during the project have been collected in the final WP of the project and guidelines for performing a damage-tolerance substantiation of integrally stiffened panels have been summarised in addition.