Probabilistic Structure-Mechanical Assessment of Rotor Discs Considering Geometry Variations

Ilko Reuter, Thomas Weiss, Matthias Voigt, Konrad Vogeler, Hartmut Schlums, Karl-Helmut Becker, Andreas Fischersworring-Bunk

abstract:

For rotating critical parts, like compressor or turbine discs of aero engines, it is essential to perform reliable life predictions. Probabilistic methods are ideal to investigate these life predictions with regard to their sensitivities and robustness. Beside other system properties, the variation of geometrical disc parameters has a strong influence on the physical system behavior.
Within this paper, the system behavior of a turbine disc is assessed with regard to its sensitivities, to enable the continuous optimization of the disc and to verify a new post-processing method. To suit this purpose, a process chain was developed from CAD-model to lifing analysis and embedded into a Monte Carlo Simulation (MCS). As input parameters geometrical parameters and their optimization ranges are used. The statistical evaluation of an MCS with regard to sensitivities is based on comparison of topologically similar locations. Similarity is achieved by the standard operation of ”mesh morphing”, in which the original mesh of the initial geometry is deformed onto the new geometry. This method is limited to small variations. Another method is remeshing of the new geometry. This makes direct comparison at identical FE-nodes impossible and post-processing is done based on significant local features. The post-processing method described in this paper is a combination of aforementioned approaches. Based on this new method, the result variables von-Mises stress and life cycles are investigated for their sensitivities to geometrical parameters within the disc bore.

reference:

Ilko Reuter, Thomas Weiss, Matthias Voigt, Konrad Vogeler, Hartmut Schlums, Karl-Helmut Becker, Andreas Fischersworring-Bunk
"Probabilistic Structure-Mechanical Assessment of Rotor Discs Considering Geometry Variations"
ASME Turbo Expo, GT2013-94589, San Antonio, 2013.