Bird Strike Simulations on Composite Aircraft Structures

Composite materials are increasingly being used for aeronautic primary structures such as wing components or fuselage panels. However, their major drawback is their vulnerability against transversal impact loads, which may lead to internal delaminations or intralaminar fiber/matrix failure. Such loads may arise from numerous impact scenarios, with bird strikes being one of the most relevant load cases. The focus of the current study is on the numerical modeling and simulation of high velocity impact loads from soft body projectiles on composite structures with ABAQUS/explicit. At first, the impact on flat composite plates is studied in experiment and simulation, which allows for the validation of the modeling methods. Some of these plates have been preloaded in tension or compression in order to investigate the influence on the mechanical behavior. It could be shown that the preloading of the plate may have a significant influence on the structural response. As a second example, the bird impact on a composite wing leading edge is treated. Adequate modeling methods for the composite material (stacked shell model), delamination failure (cohesive elements), preloading (implicit-explicit coupling) and soft body impactor modeling (coupled Eulerian-Lagrangian approach) are assessed in this paper. The final simulation results correlate well with experimental test data.