FAA Debris Mitigation Impact Test Report

Abstract : The goal of the study is the accurate prediction of the effect of uncontained engine debris on aircraft structures. This will provide airframe engineers the information required to design for damage mitigation and improved safety. The basis for predictive simulation tools lies in the experimental data, which motivates the initial development and application of codes that can adequately describe past experiments. This in turn validates the predictive capability of the codes to simulate future experiments. The LL-DYNA3D software code was developed by the Lawrence Livermore National Laboratory as a tool for simulating dynamic nonlinear events such as impact. AlliedSignal Engines (AE) is responsible for correlation and calibration of LL-DYNA3D. Events were modeled from AE experience, which includes dynamics and failure modes similar to those found in engine/airframe debris interaction. The selected events were a turbofan blade out scenario and the impact testing of curved beam specimens. The former is an actual event, the latter a controlled test. An impact test employed by AE for material characterization was adopted for use in this program. Fifteen curved beam samples were tested to obtain data needed for proper calibration of LL-DYNA3D. The materials tested were aluminum 2024 and titanium 6-4.