Developing a benchmark model for fan blade-out analysis

The development of future aircraft concepts will require a bold move away from conventional designs in order to meet environmental and performance goals. Extreme events, such as a Fan Blade-Off, can have significant influence on the design of the overall aircraft. Detailed simulation of Fan Blade-Off is computationally expensive and engine models contain a lot of design detail which may not be available at early-design stages, making it difficult to quickly analyse possible new concepts. Considering the lack of empirical data, novel modelling approaches will need to be investigated. The ability to assess these scenarios at early design stages with commensurate accuracy will help to avoid costly re-design later in the process. Additionally, by ensuring the analysis methods used are efficient both in terms of required design data and computational time, greater design variation can be investigated at relatively low cost. This paper will be focused on the development of a baseline finite element model that is representative of a commercial aircraft powerplant and can capture the expected structural behaviours during the initial stages of a Fan Blade-Off event. The model is a mid-fidelity dynamic explicit LS-Dyna model. It is constructed with shell and beam elements, and has been developed considering appropriate properties, materials, connections, pre-loading and contact. Overall powerplant response, the interaction of the engine/nacelle as well as the load transfer between the components and loads at the mounts are evaluated. The behaviour of the model is assessed by examining key performance metrics and benchmarked against available information from literature.