Methodology for Structural Integrity Analysis of Gas Turbine Blades

Vale, Tiago de Oliveira; Villar, Gustavo da Costa; Menezes, João Carlos

doi:10.5028/jatm.2012.04014311

Abstract:

One of the major sources of stress arising in turbomachinery blades are the centrifugal loads acting at any section of the airfoil. Accounting for this phenomenon stress evaluation of the blade attachment region in the disc has to be performed in order to avoid blade failure. Turbomachinery blades are generally twisted, and the cross section area varies from the root of the blade to the tip. The blade rootshape at the attachment region is of great concern. Stress concentrations are predictable at this contact region. In this paper, a finite element model has been created for the purpose of assessing stress at the joint region connecting the blade to the disc slot. Particular attention was paid to the geometric modeling of the "fir-tree" fixing, which is now used in the majority of gas turbine engines. This study has been performed using the commercial software ANSYS13.0. The disc and blade assembly are forced to move with a certain rotational velocity. Contact connections are predicted on the common faces of the blade and on the disc at the root. Solutions can be obtained to allow the evaluation of stresses. Results can be compared with the mechanical properties of the adopted material..

Keywords:
Stress Analysis; Finite Element Method; Gas Turbine Blade; Fir-treeJoint

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REFERENCES

Anandavel, K. and Prakash, R.V., 2010, "Effect of three-dimensional loading on macroscopic fretting aspects of an aero-engine blade-disc dovetail interface", Tribology International.
Beisheim, J.R. and Sinclair, G.B., 2008, "Three-Dimensional Finite Element Analysis of Dovetail Attachments With and Without Crowning", Journal of Turbomachinery, Vol.130, No. 2.
Brujic, D. et al, 2010, "CAD based shape optimization for gas turbine component design", Struct Multidisc Optim, Vol. 41, No. 4, pp. 647-659.
Chan, S.K. and Tuba, I.S., 1971, "A finite element method for contact problems of solid bodies - Part II. Application to turbine blade fastenings", International Journal of Mechanical Sciences, Vol.13, No. 7, pp. 627-639.
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Kanth, P.S., 1998, "2D & 3D FE analysis of fir-tree joints in aeroengine discs", Thesis University of Toronto.
Meguid, S.A., et al. 2000, "Finite element analysis of fir-tree region in turbine discs", Finite Elements in Analysis and Design", Vol. 35, No. 4, pp. 305-317.
Meguid, S.A., et al. 1996, "Theoretical and experimental studies of structural integrity of dovetail joints in aeroengine discs", Journal of Materials Processing Technology, Vol. 56, No. 1-4, pp. 668-677.
Papanikos, P., et al.1998, "Three-dimensional nonlinear Finite element analysis of dovetail joints in aeroengine discs", Finite Elements in Analysis and Design, Vol. 29, No. 3-4, pp.173-186.
Parks, V.J. and Sanford, R.J., 1978, "Photoelastic and Holographic Analysis of a Turbine-engine Component", Experimental Mechanics, Vol.18, No. 9, pp. 328-334.
Shankar, M. et al. 2010, "T-root blades in a steam turbine rotor: A case study", Engineering Failure Analysis, Vol.17, pp. 1205-1212.
Singh, G.D. and Rawtani, S., 1982a, "Fir tree fastening of turbomachinery blades - I deflection analysis", International Journal of Mechanical Sciences, Vol. 24, No. 6, pp. 377-384.
Singh, G.D. and Rawtani, S., 1982b, "Fir tree fastening of turbomachinery blades - II step load analysis", International Journal of Mechanical Sciences, Vol. 24, No. 6, pp. 385-391.
Song, W. et al, 2002, "Turbine blade fir-tree root design optimisation using intelligent CAD and finite element analysis", Computers & Structures, Vol. 80, No. 24, pp. 1853-1867.
Uchino, K. et al, 1986, "Three dimensional photoelastic analysis of aeroengine rotary parts", Proceeding of the International Symposium on Photoelasticity, Tokyo, Japan, pp. 209-214.
Venkatesh, S., 1988, "Structural integrity analysis of an aeroengine disc", Thesis Cranfield Institute of Technology.

Publication Dates

Publication in this collection
Jan-Mar 2012

History

Received
19 Sept 2011
Accepted
12 Nov 2011

This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

[1] Anandavel, K. and Prakash, R.V., 2010, "Effect of three-dimensional loading on macroscopic fretting aspects of an aero-engine blade-disc dovetail interface", Tribology International.

[2] Beisheim, J.R. and Sinclair, G.B., 2008, "Three-Dimensional Finite Element Analysis of Dovetail Attachments With and Without Crowning", Journal of Turbomachinery, Vol.130, No. 2.

[3] Brujic, D. et al, 2010, "CAD based shape optimization for gas turbine component design", Struct Multidisc Optim, Vol. 41, No. 4, pp. 647-659.

[4] Chan, S.K. and Tuba, I.S., 1971, "A finite element method for contact problems of solid bodies - Part II. Application to turbine blade fastenings", International Journal of Mechanical Sciences, Vol.13, No. 7, pp. 627-639.

[5] Delhelay, D. S., 1999, "Nonlinear Finite Element Analysis of the Coupled Thermomechanical Behaviour of Turbine Disc Assemblies", Thesis University of Toronto. Toronto, pp. 95.

[6] Kanth, P.S., 1998, "2D & 3D FE analysis of fir-tree joints in aeroengine discs", Thesis University of Toronto.

[7] Meguid, S.A., et al. 2000, "Finite element analysis of fir-tree region in turbine discs", Finite Elements in Analysis and Design", Vol. 35, No. 4, pp. 305-317.

[8] Meguid, S.A., et al. 1996, "Theoretical and experimental studies of structural integrity of dovetail joints in aeroengine discs", Journal of Materials Processing Technology, Vol. 56, No. 1-4, pp. 668-677.

[9] Papanikos, P., et al.1998, "Three-dimensional nonlinear Finite element analysis of dovetail joints in aeroengine discs", Finite Elements in Analysis and Design, Vol. 29, No. 3-4, pp.173-186.

[10] Parks, V.J. and Sanford, R.J., 1978, "Photoelastic and Holographic Analysis of a Turbine-engine Component", Experimental Mechanics, Vol.18, No. 9, pp. 328-334.

[11] Shankar, M. et al. 2010, "T-root blades in a steam turbine rotor: A case study", Engineering Failure Analysis, Vol.17, pp. 1205-1212.

[12] Singh, G.D. and Rawtani, S., 1982a, "Fir tree fastening of turbomachinery blades - I deflection analysis", International Journal of Mechanical Sciences, Vol. 24, No. 6, pp. 377-384.

[13] Singh, G.D. and Rawtani, S., 1982b, "Fir tree fastening of turbomachinery blades - II step load analysis", International Journal of Mechanical Sciences, Vol. 24, No. 6, pp. 385-391.

[14] Song, W. et al, 2002, "Turbine blade fir-tree root design optimisation using intelligent CAD and finite element analysis", Computers & Structures, Vol. 80, No. 24, pp. 1853-1867.

[15] Uchino, K. et al, 1986, "Three dimensional photoelastic analysis of aeroengine rotary parts", Proceeding of the International Symposium on Photoelasticity, Tokyo, Japan, pp. 209-214.

[16] Venkatesh, S., 1988, "Structural integrity analysis of an aeroengine disc", Thesis Cranfield Institute of Technology.

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