Master thesis and internship[BR]- Master's thesis : Booster casing design in fan blade out condition[BR]- Integration Internship

Abstract

In aeronautics, the mass reduction objective and the performance improvements lead to optimize increasingly the engine components. These optimizations constitute a challenge for the design methodologies and the mechanical dimensioning criteria for the engine manufacturers. In the case of compressors in turbomachine, the thicknesses of the booster outer shrouds as well as the flanges are designed under event of Fan Blade Out (or FBO for short). The FBO load case is designing for booster casing thicknesses, therefore the ability to predict and simulate the casing under a FBO event is critical to improve the booster weight. Thanks to the improvement and the development of numerical methods in rapid dynamics within Safran Aero Boosters, the understanding of mechanical phenomena is upgraded and increases the loading reliability applied on the booster casing. This work focus on the different methods to compute the casing mechanical behavior and to identify the most relevant one in order to design the casing in future developments. The assessment of existing design methods within SAB allows the identification of a so-called current method, that couples LS-DYNA (to define the load) and Samcef MECANO (to validate the strength) simulations and a so-called proposed method, that uses a LS-DYNA implementation alone to assess the FBO loads and strength of the booster casing. This work aims at validating the proposed method. To that end, a nonlinear static Samcef MECANO model is implemented to perform FBO calculation and assess the booster casing strength. The good reliability between the simulation results obtained by the SAB teams in charge of the LS-DYNA model and the FBO certification test results was highlighted. The comparison between LS-DYNA and Samcef MECANO results emphasizes more constraining mechanical quantities undergone by the casing under FBO loading and demonstrates a greater interest in using the proposed method to design the booster casing.