Fatigue Strength of Driving Shafts of Automatic Transmission Gearboxes Under Operational Torques

In a collaborative investigation of ZF Friedrichshafen AG and the Fraunhofer-Institut für Betriebsfestigkeit LBF [1], both constant and variable amplitude fatigue tests were performed on induction-hardened automatic transmission shafts made from Ck 35 mod. steel. The objectives of the project were to evaluate the safety reserves of the shafts and to apply several selected methods to assess fatigue life, to compare these methods and to gain insights for future component developments.