21st Congress of International Council of the Aeronautical Sciences, Melbourne, Australia, 13-18 September, 1998
Paper ICAS-98-7.1.3

RELIABILITY EVALUATION OF AEROSPACE COMPONENTS

Jeremic S., Bengin A.
University of Belgrade, F.R. of Yugoslavia

Keywords: reliability, aerospace components

This paper presents analytical and numerical model of flow through two-dimensional rotor cascade, solved by linear vortex panel method. Basic mathematical model is applied on real rotor blade cascade with designed airfoil. Simulation of uncertainties of random variables, that influence structural analysis and design, is based on finite element method. It was simulated static, dynamic and fatigue response of turbine blade. Sensitivity of random variables uncertainties is quantified by the sensitivity factor, useful in design, control and maintenance, as well as in meeting safety requirements. Life of turbine blades and risk associated with reusage of the blade, are calculated. For this purpose, it is introduced methodology of analysis of structure submitted to the stochastic loads, and calculated density distribution function for the first phase of system degradation. Also, it is presented statistical simulation of no balanced low pressure rotor blades, based on lows of statistics and probability. Importance of uncertainty of load function is successfully identified in the analysis of non balanced rotor. This methodology can be used for more complex components and systems in determination of reliability, safe life and associated risk. It, also, can be implemented in the definition of certification procedure, number of tests, criteria and control intervals, as well as in maintenance procedure.

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