Lifetime prediction of fatigue loaded welded joints with help of micromagnetic parameters

摘要

In the presented project different measurement techniques were examined in order to use the related parameters in a simply applicable life prediction model. The change of different micromagnetic parameters like the Barkhausen noise and the coercivity were controlled with an easy to handle magnetic multi parameter device with the aim to correlate the magnetic parameters with different stages of fatigue damage. A laser triangulation sensor was used to examine the notch geometry in order to identify possible crack initiation sites. Additionally X-ray diffraction was used to analyze the residual stresses due to the welding processes and their alteration during fatigue loading. The results of the experiments with different types of specimens show a rather good agreement between the predicted and the real life time.