An Analysis of the Thermo-mechanical Autofrettage Process of a Spherical Vessel | Chapter 1 | Engineering Research: Perspectives on Recent Advances Vol. 11

There have been numerous studies on the analysis of residual stresses and deformation for thick-walled cylindrical and spherical vessels subjected to the Autofrettage process and Re-autofrettage process. In this analysis, the results of Elastic-plastic stress distributions in a spherical pressure vessel with thermo-mechanical loads are discussed. Results of the study are obtained with Finite Element (FE) analysis. A quarter of a pressure vessel is considered and modelled with all realistic details. In addition to presenting the stress distribution of the pressure vessel, in this work, the effects of thermo-Mechanical autofrettage on different limit strengths for spherical pressure vessels are investigated. The effect of changing the load and various geometric parameters is investigated. Consequently, it can be observed that there are significant differences between the present thermo-Mechanical autofrettage and earlier (Mechanical autofrettage and Thermal autofrettage) methods of autofrettage for the predictions of Elastic-plastic stress distributions of spherical pressure vessels. Some realistic examples are considered, and results are obtained for the whole vessel by applying thermal load and mechanical load. The actual material curve is used for loading, unloading and residual stress behaviour of spherical pressure vessel. Kinematic hardening material is considered, and the effect of Bauschinger effect factors is studied with thermo-mechanical load. The equivalent Von-Mises yield criteria is used for yield criteria. behaviour of elastic-perfectly plastic is also studied and compared. The influence of Thermo-Mechanical autofrettage over stress distribution and load bearing capacity of spherical vessel is examined. The question of whether Thermo-mechanical autofrettage gives a more favourable residual compressive stress distribution and therefore extension of pressure vessel life is investigated in this analysis. It can be concluded that the autofrettage of the sphere created by Thermo-mechanical loads is more convenient and gives favourable stress distribution than mechanical and thermal loads.

 

 

Author(s) Details

Rupali
Mechanical Engineering Department, Dr. B.C. Roy Engineerng College, Durgapur, India.

 

Please see the book here :- https://doi.org/10.9734/bpi/erpra/v11/4883