Finite-Element-Based Methods for the Fatigue Design of Bolts and Bolted Joints

Due to the increase of computer performance, modern screw design is more and more based on finite element analyses. Depending on the problem, different possibilities of modelling bolted joints are reasonable. Traditionally, a nominal stress approach is used for the fatigue design of bolted joints. But, in modern lightweight constructions it is more and more common to connect threaded components directly without using a classic bolted connection. In this case a local approach has to be used. In several investigations at the Fachgebiet und Institut fur Werkstoffkunde (Chair and Institute for Materials Technology) in Darmstadt and the Robert Bosch GmbH in Schwieberdingen different concepts for a local approach have been tested for the fatigue design of threaded connections. As a result, an overview can be given, which design concept and which model can be properly used for calculations.