A research thought of establishing the mapping function based on the rules of dynamics parameters of macroscopic system due to the non-linear behavior of mesostructure for rotor system was put forward which based on finite element method

and then the dimensions of rotor systems were reduced legitimately. By simplifying the rotor model of contact structure of rod bolt in a type of engine disk appropriately

the effects of inhomogeneous rod bolt preload on the rotor macroscopic stiffness under different eccentric states of disks were analysed with ANSYS

nonlinear characteristics of stiffness were obtained.Results show that

when the bolts are evenly preloaded

along with the change of preload forces

the variation trend of nonlinear characteristics is related to the eccentric angle alteration; when half of the bolts are loose

the eccentric angle is larger while the loose preload forces are smaller

and the nonlinear characteristics are more obvious.