Int. J. Computer Aided Engineering and Technology, Vol. 5, No. 4, 2013 329 Copyright © 2013 Inderscience Enterprises Ltd. Improved fillet stresses in steam turbine blade D. Tulsidas* ACS College of Engineering, Kambipura, Mysore Road, Bangalore-560 074, Karnataka, India E-mail: tulsidala@yahoo.co.in *Corresponding author M. Shantharaja University Visvesvaraya College of Engineering, K.R. Circle, Bangalore-560 001, Karnataka, India E-mail: shantharajam@gmail.com Kenche Gowda Kumar INFOSYS India Pvt Ltd., #48, 4th Cross, 5th Main, Annapurnaeshwarinagara, Nagarbhavi 2nd Stage, RHCS Layout, Bangalore-560 091, Mysore, Karnataka, India E-mail: kumar_gowda@infosys.com Abstract: The large variety of turbo-machinery blade root geometries used in industry prompted the question if an optimum geometry could be found. The present paper outlines the improved fillet stresses in a steam turbine blade and a special attention is made on SCF of the blade root (T-root) which fails and to guarantee for safe and reliable operation under all possible service conditions. An optimum blade root was defined, as a root with practical geometry, which when loaded returns the minimum fillet stress concentration factor. Finite element analysis is used to determine the fillet stresses and Peterson’s stress concentration factor chart is effectively utilised to modify the blade root. The root is modified due to the difficulty in manufacturing the butting surface of the tang which grips the blade to the disk crowns having small contact area. Keywords: steam turbine blade root; stress concentration factor; fillet stresses; disk stresses. Reference to this paper should be made as follows: Tulsidas, D., Shantharaja, M. and Kumar, K.G. (2013) ‘Improved fillet stresses in steam turbine blade’, Int. J. Computer Aided Engineering and Technology, Vol. 5, No. 4, pp.329–342. Biographical notes: D. Tulsidas is an Assistant Professor in Mechanical Engineering at ACS College of Engineering, Bangalore. He obtained his BE in Mechanical Engineering, ME in Mechanical Engineering, specialisation in Machine Design, and pursuing his PhD from Bangalore University, Karnataka. His areas of interest are FEA in both static and dynamic and design and optimisation. He has one year of industry and ten years of teaching experience.