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Residual stress analyses of re-autofrettaged thick-walled tubes

Farrahi, G. H ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ijpvp.2012.07.007
  3. Publisher: Elsevier , 2012
  4. Abstract:
  5. In this paper the effect of the re-autofrettage process on the residual stress distribution at the wall of a thick-walled tube is considered. For accurate material behavior modeling, it is assumed that the yield surface is a function of all the stress invariants. Also for estimating the behavior of the material under loading-unloading process, a modified Chaboche's hardening model is applied. For evaluation of this unloading behavior model a series of loading-unloading tests are conducted on specimens that are made of the high strength steel, DIN1.6959. In addition the finite element simulations are implemented to simulate the re-autofrettage process and to estimate the residual stresses. The numerical results show that the re-autofrettage process without heat treatment only improves the residual stress distribution in high autofrettage percentage and for low autofrettage percentage this method is not beneficial. However, the re-autofrettage process with ''heat soak'' treatment generally improves the residual stress distribution
  6. Keywords:
  7. First stress invariant ; Lode angle parameter ; Residual stress distribution ; Autofrettage ; Behavior model ; Finite element simulations ; Hardening model ; Loading-unloading tests ; Lode angle ; Material behavior ; Nonlinear kinematic hardening ; Numerical results ; Re-autofrettage process ; Stress invariants ; Thick-walled tube ; Yield surface ; Hardening ; Numerical methods ; Residual stresses ; Stress concentration ; Tubes (components) ; Unloading ; Loading
  8. Source: International Journal of Pressure Vessels and Piping ; Volume 98 , 2012 , Pages 57-64 ; 03080161 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0308016112000920