Dynamic probabilistic analysis of stress and deformation for bladed disk assemblies of aeroengine

BAI Bin(白斌), BAI Guang-chen(白广忱)

(School of Energy and Power Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, China)

Abstract:In order to describe and control the stress distribution and total deformation of bladed disk assemblies used in the aeroengine, a highly efficient and precise method of probabilistic analysis which is called extremum response surface method (ERSM) is produced based on the previous deterministic analysis results with the finite element model (FEM). In this work, many key nonlinear factors, such as the dynamic feature of the temperature load, the centrifugal force and the boundary conditions, are taken into consideration for the model. The changing patterns with time of bladed disk assemblies about stress distribution and total deformation are obtained during the deterministic analysis, and at the same time, the largest deformation and stress nodes of bladed disk assemblies are found and taken as input target of probabilistic analysis in a scientific and reasonable way. Not only their reliability, historical sample, extreme response surface (ERS) and the cumulative probability distribution function but also their sensitivity and effect probability are obtained. Main factors affecting stress distribution and total deformation of bladed disk assemblies are investigated through the sensitivity analysis of the model. Finally, compared with the response surface method (RSM) and the Monte Carlo simulation (MCS), the results show that this new approach is effective.

Key words:bladed disk assemblies; probabilistic analysis; finite element model; extremum response surface method; sensitivity analysis; transient dynamic analysis