Explicit Finite Element Analysis of 2024-T3/T351 Aluminum Material Under Impact Loading for Airplane Engine Containment and Fragment Shielding; Final rept

摘要

Uncontained aircraft engine failure can cause catastrophic damaging effects to aircraft systems if not addressed in the aircraft design. The Federal Aviation Administration has commissioned and coordinated a research program associating industry, government agencies, national research laboratories, and universities to conduct research to mitigate the damaging effects of uncontained engine failure and improve the numerical modeling capability of these uncontained engine events. This joint Boeing and George Washington University report covers high strain rate material modeling efforts that have been conducted to simulate and validate ballistic impact tests on 2024-T3/T351 aluminum alloy, which is one of the most extensively used materials in the aircraft industry. Ballistic limits were evaluated using explicit finite element (FE) simulations based on the corresponding ballistic impact experiments for different target thicknesses that were conducted at the University of California at Berkeley. LS-DYNA was used as a nonlinear explicit dynamics FE code for the simulations. The Johnson-Cook material model was employed as a thermo-visco-plastic material model coupled with a nonlinear equation of state and an accumulated damage evaluation algorithm for the numerical simulations. Predictive performance of the numerical models is discussed in terms of the material characterization efforts and material model parameter sensitivities.