Abstract

Rotating discs with variable thickness and nonhomogeneous material properties are frequently used in industrial applications. The nonhomogenity of material properties is often caused by temperature change throughout the disc. The governing differential equation presenting this problem contains many variable coefficients so that no possible analytical closed form solution for this problem. Many numerical approaches have been proposed to obtain the solution. However, in this study the Finite Element Method (FEM), which presents a powerful tool for solving such a problem, is used. Thus, a turbine disc modeled by using ax symmetric finite elements was analyzed. But, in order to avoid inaccuracy of the stress calculation quite fine meshing is implemented. The analysis showed that maximum displacement occurs at the boundary of the disc, either at the outer or inner boundary, depending on the loadings. The maximum radial stress occurs at an area in the middle of the disc which has the smallest thickness. In this study, rotational blade load was shown to give the largest contribution to the total displacement and stress. Also, the radial displacement and stress in a disc with variable thickness are found to be affected by the contour of the thickness variation. In general, the results obtained show excellent agreement with the published works.

Keywords:

Finite element method, nonhomogeneous material properties, rotating disc, variable thickness,

References

1. Barack, W.N. and P.A. Domas, 1976. An Improved Turbine Disk Design to Increase Reliability of Aircraft Jet Engines. NASA Lewis Research Center, NASA CR-135033, R76AEG324
   
2. Bayat, M., M. Saleem, B.B. Sahari, A.M.S. Hamouda and E. Mahdi, 2008. Analysis of functionally graded rotating diskswith variable thickness. Mech. Res. Commun., 35: 283-309.
   CrossRef    
3. Boresi, A.P. and S. Richard, 2003. Advanced Mechanics of Materials. 6th Edn., John Wiley and Sons, NY.
   
4. Claudio, R.A., C.M. Branco, E.C. Gomes and J. Byrne, 2002. Life prediction of a gas turbine disc using the finite element method. Jornadas de Fractura. Retrieved from: ltodi.est.ips.pt/.../RC_CMB_ EG_JB_Life%20Prediction%20of%20a%20.
   
5. Den Hartog, J.P., 1987. Advanced Strength of Materials. Dover Publications. New York.
   
6. Elhefny, A. and L. Guozhu, 2012. Stress analysis of rotating disc with non-uniform thickness using finite element modeling. Proceeding of the 2012 International Conference on Engineering and Technology (ICET). Cairo, pp: 1-5.
   CrossRef    
7. Gamer, U., 1985. Stress distribution in the rotating elastic-plastic disk. ZAMM-Z. Angew. Math. Me., 65(4): 136-137.
   
8. Guven, U., 1997. The fully plastic rotating disk with rigid inclusion. ZAMM-Z. Angew. Math. Me., 77: 714-716.
   CrossRef    
9. Guven, U., 1998. Elastic-plastic stress distribution inrotating hyperbolic disk with rigid inclusion. Int. J. Mech. Sci., 40: 97-109.
   CrossRef    
10. Hassani, A., M.H. Hojjati, G. Farrahi and R.A. Alashti, 2012. Semi-exact solution for thermo-mechanical analysis of functionally graded elastic-strain hardening rotating disks. Commun. Nonlinear Sci., 17: 3747-3762.
    CrossRef    
11. Hojjati, M.H. and S. Jafari, 2007. Variational iteration solution of elastic non uniform thickness and density rotating disks. Far East J. Appl. Math., 29(2): 185-200.
    
12. Hojjati, M.H. and A. Hassani, 2008. Theoretical and numerical analyses of rotating discs of non-uniform thickness and density. Int. J. Pres. Ves. Pip., 85: 694-700.
    CrossRef    
13. Jahed, H., F. Behrooz and B. Jalal, 2005. Minimum weight design of inhomogeneous rotating discs. Int. J. Pres. Ves. Pip., 82: 35-41.
    CrossRef    
14. Leopold, W.R., 1984. Centrifugal and thermal stresses in rotating disks. ASME J. Appl. Mech., 18: 322-6.
    
15. Liu, J.S., T.P. Geoffrey and P. John Clarkson, 2002. Optimization of turbine disk profiles by metamorphic development. J. Mech. Des., 124(2): 192-200.
    CrossRef    
16. Maruthi, B.H., M. Venkatarama Reddy and K. Channakeshavalu, 2012. Finite element formulation for prediction of over-speed and burst-margin limits in aero-engine disc. Int. J. Soft Comput. Eng., 2(3).
    
17. Sharma, J.N., S. Dinkar and K. Sheo, 2011. Analysis of stresses and strains in a rotating homogeneous thermoelastic circular disk by using finite element method. Int. J. Comput. Appl., 35(13): 0975-8887.
    
18. Stodola, A., 1927. Steam and Gas Turbines. Vol. 1. McGraw-Hill, New York.
    
19. Timoshenko, S.P. and J.N. Goodier, 1970. Theory of Elasticity. McGraw-Hill, New York.
    CrossRef    
20. You, L.H., Y.Y. Tang, J.J. Zhang and C.Y. Zheng, 2000. Numerical analysis of elastic-plastic rotating disks witharbitrary variable thickness and density. Int. J. Solids Struct., 37: 7809-7820.
    CrossRef    

Competing interests

The authors have no competing interests.

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