Abstract

A stress relief groove is introduced in the R area and the stress is analyzed using a finite element method (FEM). Then the relief of the stress concentration in the vicinity of the pressure vessel is measured based on these results. When de-signing a stress relief groove, the lever must overhang the groove (L> 0). By introducing a stress relief groove to the R area, maximum stress on the lever guide can be reduced by 10%. This enables the reduction of the maximum stress (Mises stress) to be less than the fatigue strength. Furthermore, the location where maximum stress occurs on the lever guide changes in accordance with the clearance between the lever and lever guide. This identified the need to take into account the deviation factor such as design clearance in modeling process.