An Explicit Numerical Modeling of Soft Body Impact Damage in Metallic Airplane Structures

This paper tackles the problem of numerical prediction of bird strike induced damage in real aeronautical structures using highly detailed finite element models and modern numerical approaches. Due to the complexity of today's aeronautical structures, numerical damage prediction methods have to be able to take into account various failure and degradation models of different materials. The work presented in this paper is focused on damage modeling in metallic items of aeronautical structures. Abaqus/Explicit has been employed to perform geometrical and material nonlinear transient dynamic analyses. The problem of soft body impacts has been tackled by applying a hybrid Eulerian Lagrangian technique, thereby avoiding numerical difficulties associated with extensive mesh distortion. Eulerian modeling of the bird impactor resulted in a more realistic behavior of bird material during impact. The main focus of the work presented in this paper is the application of damage prediction procedure in damage assessment of bird impact on a typical large airliner slat structure and comparison with damage observed during exploitation of a real slat structure. Due to the high cost of gas-gun testing of aircraft components, experimental testing on the real flap structure could not have been performed. Validation of the hybrid formulation in solving bird strike problems has been achieved by comparison with available references.