The EU project CleanSky/Bird Strike deals experimentally and numerically with bird strikes on wing structures made of CFRP structures. The European consortium consists beside the RWTH Aachen University of the University of Patras (ISTRAM – Institutes of Advanced Materials and Structures, Greece) and Milan (POLIMI – Politecnico di Milano, Italy) and the industrial company SAAB, CI (Composite Impulse GmbH & Co) and DANTEC (Dantec Dynamics GmbH).
The investigations are focused in the first phase of impact events on plate structures. The bird body is experimentally idealized by a gelatin mass and shot at the CFRP plates using hailstone cannon. The here considered plate consists of several unidirectional plies with a quasi-isotropic and symmetrical lay-up. The Institute of Structural Mechanics and Lightweight Design has the task to develop an LS-Dyna-FE model that can calculate the bird strike process. The numerical results will be validated with experimental data later. A further subtask is the structural and mechanical design of the experimental setup, as well as the definition of the boundary conditions of the plate, so as to achieve an agreement with the theoretical assumptions.
For this purpose, the CFRP plate is divided into several sub laminates and connected with each other with a tie-break contact. With the tie-break contact the delamination behavior of the plate can be predicted. In addition, the CFRP plate is supported at its edges by silicone elastomer pads. The elastomer allows a free/free supporting condition of the CFRP plate and it can be additionally described and modeled numerically.
The verified and validated prediction model is ultimately used to calculate bird strike processes on wing leading edges with the aim to design and sizing appropriate wing structures.