Investigation of Novel Fe-Based Modeling Aproaches for Stifened CFRP Aircraft Structures

Reduced representations of stiffened shell structures are required for an efficient FE-based evaluation of different unconventional fuselage stiffener layouts for example in layout optimizations. The use of omega profiles adapted to fiber placement technologies introduces additional challenges. Three different modeling approaches are introduced, each combining a numerical and an analytical model. Two approaches are based on existing numerical models and are combined with analytical models. In the novel third approach, extra shell elements to explicitly model the width of the omega stiffener are added. In an evaluation, the calculated displacements of four characteristic load cases for different wide omega profiles are compared to a reference. The results show small deviations for the new modeling approach. Under tension and bending loads, mean deviations below 1 % are achieved. For torsional loads, the mean deviation can be reduced to 3 % compared to 30 % using a conventional approach.