To improve the accuracy of gas turbine pull-rod rotor modeling

a virtual material layer was introduced at the contact surface of the wheel to characterize the contact effect. By the mathematical statistical model and gaussian distribution function

the mechanical model of the normal contact stiffness of contact surface was obtained

and the contact characteristics under different parameters were analyzed. Based on the constitutive relation of the deformation of material mechanics

the elastic modulus and poisson′s ratio of the virtual material layer were derived

and the contact layer was modeled. The results of dynamic calculation show that

under rigid support

the contact effect caused by the change of preload has a significant influence on the fourth-order critical speed

and the speed deviation can reach 2.31%. The results of introducing nonlinear oil film force show that the increase of preloading force leads to the advance of all motion states

and the dynamic results of solid rotor and rotor considering the contact of preloading force are quite different. The introduction of virtual material layer simplifies the modeling process of gas turbine rotor considering the contact effect and reflects the weakening effect of the contact effect on the transverse vibration stiffness of the rotor.