A new method of micro-slip contact normal pressure modeling and its application in the dynamic analysis of the dovetail–tenon–mortise jointed blades

Abstract

In this paper, a contact slip mechanics model based on pressure distribution is developed, it is formed from multiple contact pairs and can define the contact behavior between contact interfaces. First, we establish the jointed structure's finite element model to calculate the contact interface's nodal pressure. Following this calculation, applying the cubic spline interpolation to the nodal pressure data, we obtain the contact surface pressure. Then using the theory of load equivalence, the contact surface pressure is converted into an equivalent load. The equivalent load is used as the normal pressure of the contact pairs place on the contact surface nodes. Subsequently, to verify the developed modeling approach, we establish a simplified blade model with the tenon–mortise structure for trial calculation. Finally, the nonlinear frictional force is linearized to solve the nonlinear differential equation by the incremental harmonic balance method (IHBM). The results show that the tenon–mortise contact surface exhibits micro-slip characteristics, which means that the pressure distribution characteristics of the contact surface are retained. The contact slip mechanics model developed in this paper is general which can be applied in modeling the contact surfaces of other joints.