Influence of the Contact Interfaces on the Dynamics and Power Flow Behavior of the Bolted Structure

Bolted joints are widely used for the assembly of mechanical components to provide continuity of the structure and transfer internal actions (i.e. forces and moments) from one member to another. Contact and dry friction at the jointed interface have a great influence on the dynamical performance of the assembly, especially for light-weight and heavy-loaded structures, such as the aero-engine. In this paper, the nonlinear dynamic response of a turbo-engine casing in the presence of bolted flanges is studied, using one reduced order model of an elementary casing sector with means of node-to-node contact elements. While the vibration power flow method for the structural system with frictional interfaces is proposed to reveal effects of energy dissipation at contact interfaces. It can be concluded that the resonance frequencies and vibration responses of the bolted structures are influenced by the interfacial contact state, and the damping induced at the slipping contact area surrounding the bolt decreased the vibration response. Power flow through the bolted structure are visualized, which clarified the energy dissipation at the bolted interfaces.