抄録
A crystalline FEM theory which incorporates the Bausinger's effect is applied to investigate the relationship between the crystal direction and the progress of plastic deformation localization and irreversible slip generation, which are part of the fatigue crack initiation process, by calculating the cyclic deformation behavior of a f.c.c. crystal with high Schmid's factor which is buried in a large crystal with low Schmid's factor.
As results, the followings are found :
1) In the same manner as the results for f.c.c. single crystal analyzed in the previous reports, plastic deformation localization and irreversible slip generation in the course of loading history can be simulated by using the crystalline FEM code developed in the previous reports when the buried crystal is set in the specific direction.
2) Plastic deformation localization and irreversible slip generation appears only when all of the following conditions are satisfied : a) direction of crystal is set so that the coplaner or non-coplaner double slip occurs ; b) the slip directions of two activated systems meet the free surface at the same angle ; c) the slip planes of two systems meet the free surface at the same angle.
3) The properties of cyclic deformation behavior in the coplaner double slip cases are affected more seriously by the deviation of loading direction than the ones in the non-coplaner double slip cases.
