Mustafa Dindar

TURBINE BLADE PROBABILISTIC ANALYSIS USING SEMI-ANALYTICAL SENSITIVITIES

Over the years engineering design practices have matured to a point where significant performance gains are not likely obtainable with further enhancement of existing deterministic analyses. Future design improvements will require that engineers address the underlying uncertainty present in the parameters of engineering models. This paper investigates the application and implementation of first-order reliability and finite element semi-analytical sensitivities to the probabilistic analysis of an aircraft engine turbine blade. State-of-theart computer aided design (CAD) techniques are employed to automate and coordinate finite element meshing for shape sensitivity calculations. Random variables are used to model uncertainty in turbine blade shape parameters. Two reliability techniques are examined: the mean-value first-order (MVFO) and the Hasofer-Lind Rackwitz-Fiessler first-order (HLRF) reliability methods. The HLRF requires accurate gradient information which is accomplished via a semi-analytical finite element technique. Computational costs of the probabilistic analyses and a discussion of implementation issues are presented.