Effect of cold driving process on fatigue life of helicopter fuselage joints

Cold driving is a common procedure in aeronautical structures in presence of riveted holes; this process has influence on the fatigue life of the whole riveted joint. Using detailed FE models comprehensive of the rivet forming operation, the effect of the squeeze force on fatigue life of the joint has been investigated. Different multiaxial fatigue criteria (Sines, Crossland, KakunoKavada and Papadopoulos) have been used in the fatigue evaluations in order to consider the complete stress state of the riveted hole (comprehensive of the residual stress field). The numerical analyses have been supported by an experimental test carried out on a panel specimen from rotorcraft frame.