DBEM Crack Growth Simulation and Experimental Results for a Multi-Layer and Multi-Material Aeronautic Panel
A special specimen was created cutting a rectangular notched area from the surrounding of the upper left corner of a wide body aircraft door. This part of the aircraft skin is made of different layers with variable thickness and material (titanium or aluminum). Then a fatigue traction load was applied and some notches were cut in the different layers in order to speed up the crack initiation and reproduce a realistic crack scenario. Such through cracks were monitored during their propagation along the specimen width, in order to have available for the simulation a realistic initial scenario and experimental propagation data useful for the correlation with the simulated crack path and growth rates. In particular an innovative DBEM modelling approach was devised, using a commercial code (BEASY), capable of explicitly modelling the different test article layers with their rivet connections even in a two-dimensional approach. The results of the simulation show a satisfactory correlation with the experimental crack path and growth rates even for such a complex problem: three different panels (one skin with two doublers), made of different materials, each one with a variable thickness and connected through numerous rivets (whose shear stiffness is taken into account for the simulation).
M.H. Aliabadi, Qingfen Li, Li Li and F.-G. Buchholz
R. G. Citarella et al., "DBEM Crack Growth Simulation and Experimental Results for a Multi-Layer and Multi-Material Aeronautic Panel ", Key Engineering Materials, Vols. 324-325, pp. 1123-1126, 2006