Numerical and databased investigations on the fatigue of cruciform joints with gaps

摘要

The paper deals with investigations on the fatigue resistance of the load-carrying cruciform joint with gaps. The aim is to define limits of specific acceptable imperfections, since these do not always necessarily affect the fatigue strength. Different geometrical influences on the fatigue strength of the load-carrying cruciform joint with gaps are analysed numerically. Numerical simulations comprise effective notch stress calculations, which have been compared to fatigue test results from literature, documented in a fatigue test database. A larger gap in combination with a smaller weld size leads to the unfavourable failure at the weld root. For the specific geometrical configurations, borderline functions defining the failure location on the basis of local weld geometry have been defined. Finally, the most interesting configurations are presented, which will be tested experimentally in a subsequent fatigue test program.