Abstract: When calculating the response of the turbine blades with a dry friction damper, the tangent contact stiffness between the contacts of the damper affects the conditions of the contact state conversion directly. In this paper,theoretical derivation was combined with numerical simulation method. By establishing a flat contact model with rounded edges, the force distribution of the contact surface was given. Based on the displacement distribution of contact points, the relationships between tangent contact stiffness and normal pressure was derived. Besides, the relationship between contact stiffness and normal pressure was obtained by finite element simulation as well.Therefore, we can obtain the contact stiffness quickly and accurately to more accurately analyze the state changes between combined surfaces.

Key words: dry friction damper, contact model, flat sheet with rounded edges, contact stiffness, finite element simulation