In order to obtain a better structure type and reduce stress concentration to achieve better fatigue strength

the dual arcs transition on tenon-mortise joints was examined to find out its influence on stress distribution. Geometric restrictions on dual arcs transition were derived to support design optimization and modifications. Dual arcs transition were employed on two-teeth tenon-mortise joints of turbine disk and the stress assessment on the structure was performed. The dual arcs transition was proved effective in reducing stress concentration and improving structure strength. Multivariable optimization is carried out based on Isight platform using non-linear quadratic programming language (NLQPL) method. Better structural parameters are achieved to reduce stress concentration

and the maximum stress decreases by 19.98%.