Abstract: The research work of this paper is related to the stress analysis of the cold-expanded and interference-fitted fastener holes.The study uses a combined hardening model and the associated elastic-plastic finite element program.In the analysis of cold expanded holes,good correlation between the available test results and the present calculations is achieved for two kinds of tested materials with properly selecting the combination proportion of isotropic hardening and kinematic hardening.The procedure of double expansion and the interaction between interference fitting and a remote tension cycle are also taken into account by the analysis of two calculation examples.

Key words: cold hardening, fitting, residual stress