Micro-slip properties for dry friction of blade root joints

Several contact pairs were built on the contact surface to simulate the micro-slip at the blade root joint. Control variate method was employed to gain the hysteresis loop with friction force and relative displacements in two-dimensional blade root joints contact surface under steady vibration. Analysis and assessments were carried out for parameters such as reference nodes, mesh configuration, tangential and normal loads, contact stiffness and friction coefficient, providing a new insight for investigating the micro-slip property of blade root dry friction. The results showed that when investigating the behavior of blade root joints with micro-slip model, the choices of different parameters had influence on the dry friction properties. The contact element amount affected the accuracy of the results, and the reference nodes used gave different descriptions to the hysteresis loop. Tangential load made the relative displacement in hysteresis loop different. The decrease of normal contact stiffness can increase the relative displacement and micro-slip region. The increase of tangential contact stiffness made the blade root move easier with macro-slip like rigid motion. Friction coefficient and normal pressure increased the micro-slip region, while the influence was not absolutely the same. Meanwhile, the damping effects of contact parameters were investigated by way of dissipated energy.