Compact model and identification process for friction induced damping in a rotational joint with flawed surfaces

AbstractIt is well known that bolted joints have significant influence on the dynamical behavior of assembled structures due to formation of damping. This paper focuses on damping caused by dry friction in a rotational joint. Friction can be either induced by micro-slipping or macro-slipping. This paper describes the design of a new experimental device intended to measure damping caused by friction and partial slip in rotational joints. An original method for measuring dissipated energy in rotational joints with plan-plan contact is proposed. This method is based on Lagrange formalism and allows to measure accurately forces and torques only with accelerometers. These techniques are available for very small displacements that occur in micro-slip and partial slip of surfaces in contact and are still available for large displacements (macro-slip). An analytical compact model based on the Greenwood model is studied. The experimental results and simulations used to quantify the dissipated energy in order to compute the damping ratio are presented and discussed