Stress Distribution, Frequency Response, Mode Shape of Twisted and Untwisted Compressor Blisk under Different Pressure Loading Conditions

Abstract

Bladed integrated disk (blisk) is a turbo engine compressor part that is specially designed to permit an adequate amount of compressed air into the burner. Blisk is used to enhance the short take-off and landing capability of the multirole fighter aircraft, because it has both rotary disc and blade. The design of the blisk needs to be carried out carefully since it is a critical part in respect of design and is subject to stringent controls. Modelling and analysis of compressor blisk diminish the complications in the design process and to enhance the quality of the design phase. In this research, finite element modelling and analysis of the compressor blisk blade is carried out to determine the stress developed in high-pressure compressor blisk for different pressure loading conditions and at three different blade orientations. Stress distributions, displacements, frequency response and mode shapes over the entire geometry of the blade were recorded under natural frequency and displayed. The stress developed on twisted compressor blisk is more than the untwisted one and it is increasing because of the increment in stress concentration areas and residual stresses. The frequency response and mode shape of twisted blades are higher and lower respectively than the untwisted blades because of the imbalanced residual stress development.