AN AXISYMMETRICAL METHOD OF ELASTIC-PLASTIC ANALYSIS CAPABLE OF PREDICTING RESIDUAL-STRESS FIELD

Linear elastic solution of an axisymmetric boundary value problem is u sed as a basis to generate its inelastic solution. This method treats the material parameters as field variables. Their distribution is obta ined as a part of solution in an iterative manner. Two schemes of upda ting material parameters are discussed and compared. A procedure for c alculation of residual stress field is presented, Application of the m ethod to autofrettage is presented Residual stress calculation based o n actual material curve, isotropic and kinematic hardening models, and variable Bauschinger effect factor (BEF) is carried out, It is conclu ded that consideration of dependency of BEF on plastic strain makes si gnificant changes to residual hoop stress near the bore for low-level autofrettage. However, this dependency is insignificant for high-level autofrettage, Results obtained here are shown to be in good agreement with experimental and finite element results.