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SEA Applied to the Prediction of High Frequency Vibrations in Aircraft Engines

Periodic Reporting for period 1 - VibSEA (SEA Applied to the Prediction of High Frequency Vibrations in Aircraft Engines)

Reporting period: 2019-04-01 to 2020-09-30

Designed to achieve reduction in fuel consumption, the Ultra-High Bypass and High Propulsive Efficiency Geared
Turbofan engine incorporates evolutions likely to produce high frequency (HF) vibration excitations which propagate
through the structure.

Numerical simulation is an efficient tool to control vibrations hence supporting the mechanical
design. Where Finite Element (FE) based approaches show limitations due to computational hardware performances
and HF dispersion management, Statistical Energy Analysis (SEA) stand as proven and effective method for this
frequency range to predict the vibrational energy transfers across partitions – subsystems – of a structure.

Challenges of SEA modelling consist of the structure partitioning which usually requires expertise and the accuracy loss at lower
frequencies where the high stiffness of parts or complexity of junctions counter the method initial assumptions. Those
statements depend strongly on the studied structure, therefore the objective of the proposed project is to develop
and demonstrate a SEA modelling process to predict the vibration propagated in a typical complex engine frame.
04/19 - 10/20

During the first period of VIBSEA, the project progressed in all Work Packages.

Within WP1, the State of the Art has been written. It aims at introducing the principle, history and main references of SEA and Hybrid FE SEA as prediction methods to evaluate the high frequency range of structural vibrations.
Within WP2, Test Matrices of the experimental approaches have been detailed. They include the theoretical and practical basics to apply these methods. They will permit measuring the necessary data to post-treat the key SEA parameters in WP7.
Within WP3, the mechanical function of the test bench has been developed. It permits limiting the interaction between the test frame and the bench.
Within WP4, an optical detection method has been designed and developed to reduce the time measurement and to get more accurate results.
Within WP5, first steps of modelling process have been achieved. A global FE Model has been developed and fragmented into individual substructures. These FE based substructures are currently analysed to support the SEA Subsystems and couplings qualification. Complex components are analysed with specific focus.
Beyond the state of the art, the project's goals are to extend the SEA methodology to a complex engine frame. The expected results until the end of the project are to be able to provide sufficiently accurate SEA models that can be used and updated with experimental data.

The project will permit to develop and to improve post processing tools for the virtual and experimental SEA. Consortium members will be able to propose extended and improved SEA technical services to customers in aeronautic but also to other markets such as automotive, off-road vehicles, energy fields and railway.