Intelligent Approach to Robust Design Optimization of a Rotor System due to Its Support Stiffness Uncertainty

Table 3

Initial ranges of the design variables (unit: N/m).

Design variables; kj	Low boundary	High boundary
k 1	1 × 10^7	3 × 10^7
k 2	7.5 × 10^8	1.25 × 10^9
k 3	7.5 × 10^8	1.25 × 10^9