Study on the Material Parameter Extraction of the Overlay Model for the Low Cycle Fatigue(LCF) Analysis

Abstract : This work was focused on the material parameter extraction for the isothermal cyclic deformation analysis for which Chaboche 1) (Combined Nonlinear Isotropic and Kinematic Hardening) and Overlay 2) (Multi Linear Harde-ning) models are normally used. In this study all the parameters were driven especially based on Overlay theories. A simple method is suggested to find out best material parameters for the cyclic deformation analysis prior to the isothermal LCF(Low Cycle Fatigue) analysis. The parameter extraction was done using 400 series stainless steel data which were published in the reference papers. 3) For simple and quick review of the parameters extracted by suggested method, 1D FORTRAN program was developed, and this program could reduce the time for checking the material data tremendously. For the application to FE code ABAQUS user subroutine for the material models was developed by means of UMAT(User Material Subroutine), and the stabilized hysteresis loops obtained by the numerical analysis were in good harmony with test results.